Burke’s Cancer Dictionary


0.05 level
A 5% chance that two things are really the same when they were found to be different. Allows us to reject the null hypothesis of no difference with a high degree of certainty that we are correct. The likelihood that if the test was done one hundred times the same result would be observed by chance 5% of the time. If that likelihood is 5% or less, i.e., less than one out of twenty, it is said to be significant, which means that it is unlikely to be due to chance. Five percent of the time the result could have occurred just by chance variation in the variables.


See Analysis of variance.
Ablation, hormonal
In the management of hormone-responsive cancer, hormonal ablation involves treatments that reduce the level of hormones in the blood to very low or undetectable levels.
A collection of pus in a tissue resulting from the disintegration of tissue, mainly caused by infection.
Abscopal effect
The hypothesis that a treatment directed at a tumor at one site can affect tumors at other locations in the body. It suggests that a local therapy, e.g., radiation, surgery, hyperthermia, can have non-local therapeutic effects. It was first proposed by Dr. R.H. Mole. (Br J Radiol 1953;26:234-41).
Absorption coefficient
A unit of measure used in nuclear medicine. It is the amount of radiation that is absorbed per unit of thickness, per unit of mass, or per atom of an absorber.
A chemical substance with a pH lower than 7.0, a pH level of more than 7.0 is alkaline (also known as a basic substance), and a pH of 7.0 is neutral in the body.
The parts of a gland (such as the breast) in which fluid (or milk) is produced (singular: acinus). Also, in the prostate, prostate specific antigen (PSA).
Acquired mutations
Gene changes that arise within individual cells, that are not repaired, and that accumulate throughout a person's lifetime. Also called somatic mutations.
Occurring suddenly or within a short period of time.
Cancer derived from glandular tissue, such as breast tissue, or in which tumor cells form a glandular structure.
A statistical procedure to minimize differences in the characteristics among patients that are being compared in a study. For example, if two groups that have different mean ages are being compared, the age of each subject can be put into a multivariate statistical model and differences between the groups can be observed as if there were no differences in age between the groups.
Adjuvant therapy
A therapy given to augment or simulate some other form of treatment such as surgery. Adjuvant therapy after surgery could be hormonal therapy, chemotherapy, immunotherapy, or radiotherapy.
(1) A person who speaks for a sick patient. (2) A person who represents patients on a peer review panel, Institutional Review Board, or other body that assesses the safety of studies involving patients. (3) A person who helps collect money for disease research or treatment.
A gelatinous material used as a culture media to grow cells.
A substance or compound, such as a drug, that binds to the same cell receptors as a natural substance and produces a similar physiological effect. A substance can be an agonist in one tissue and an antagonist in other tissue.
A chemical substance with a pH level of more than 7.0 is alkaline (also known as a basic substance), a pH lower than 7.0 is acidic, and a pH of 7.0 is neutral in the body.
Alkylating agent
Highly reactive chemical compounds capable of forming covalent linkages with various nucleophilic groups in proteins and nucleic acids. Five major classes of alkylating agents are used as chemotherapeutic (antineoplastic or immunosuppressive) agents: Nitrogen mustards (mechlorethamine, cyclophosphamide); ethylenimine derivatives (thiotepa); alkyl sulfonates (busulfan); nitrosoureas (carmustine, streptozocin); and triazines (dacarbazine). The major biological effects of alkylating agents are produced by attacks on DNA, causing cross-linking of DNA strands, chain fission, or removal of bases. Bifunctional agents, which can form cross links and block DNA replication, are primarily cytotoxic; monofunctional agents are more mutagenic and carcinogenic. Alkylating agents are not cell-cycle specific; however, cell killing occurs primarily in rapidly proliferating tissues in which there is insufficient time between mitoses for DNA repair to reverse the effects of the agent. Hematopoietic, gastrointestinal, and reproductive tissues are particularly sensitive to alkylating agents, Side effects related to cells that rapidly replicate in the body include depression of blood cell counts, amenorrhea, impaired spermatogenesis, damage to mouth, esophageal, stomach and intestinal mucosa, and alopecia.
Alkyl sulfonates
A type of chemotherapy, an alkylating agent, includes busulfan.
All-cause mortality
Death due to any cause, not just due to cancer.
Different forms of the same gene. Every individual has two forms of each gene (one on each of the paor of chromosomes), one from each parent. Different alleles produce variations in inherited characteristics, such as eye color or blood type.
Allele, dominant
A gene that is expressed regardless of whether its counterpart allele is on the other chromosome. Autosomal dominant disorders are produced by a single mutated dominant allele, even though its corresponding allele is normal.
Allele, recessive
A gene that is expressed only when its counterpart allele on the other chromosome is also recessive (not dominant). Autosomal recessive disorders develop in people who receive two copies of the mutant gene, one from each parent who is a carrier.
Tissue that is obtained from a person who is not the recipient of the tissue.
Allogenic transplant
The transplantation of tissue from one person to another. See Autologous transplant.
Hair loss anywhere on the body. In cancer patients it can be caused by chemotherapeutic drugs and by radiation therapy.
The absence or discontinuation of menstruation due to starvation and other conditions, normal menopause (usually occurs around 51 years of age), or chemotherapy.
Amino acid
The building blocks of proteins. There are 20 amino acids; 11 can be created by the body, and 9 (essential amino acids) that must be obtained through the diet.
Amplification, DNA, RNA
An increase in the number of copies of a specific DNA or RNA fragment.
Pain-relieving medicines, for example, aspirin, acetominophen, or morphine.
Analysis of variance
A statistical technique to determine the isolated contribution of one of several categorical independent variables to variation in the mean (average) of a continuous dependent variable. See Variable.
Dealing with the physical structure of organisms, specifically, the anatomy of the body.
A class of hormones produced in larger amounts in men than in women and in large amounts cause masculinization, for example, testosterone.
Loss of feeling or sensation. Although the term is used for loss of tactile sensibility, or of any of the other senses, it is applied especially to loss of the sensation of pain as it is induced to permit performance of surgery or other painful procedures. Its relationship to consciousness is complex since one can be anesthesized and conscious. A patient undergoing surgery will receive and a general anesthetic, a paralyzing agent, and an agent to cause loss of consciousness.
The characteristic of having either fewer or greater than the normal number of chromosomes in a cell. This usually indicates an abnormal cell.
The development of new blood vessels.
Angiogenesis factor
A substance that causes the growth of new blood vessels, found in tissues with high metabolic requirements such as cancers and the retina. It is also released by hypoxic macrophages at the edges or outer surface of a wound and initiates revascularization in wound healing.
A substance (including a drug) that binds to a receptor on a cell but does not produce any physiological effects and it blocks the binding by any other substance to that receptor.
Antagonists, hormone
Chemical substances that inhibit the function of the endocrine glands, the biosynthesis of their secreted hormones, or the action of hormones upon their specific sites. For example, estrogen antagonists. Some substances (including drugs) have both antagonist and agonist effects depending on the tissue and their concentration.
Located toward the front.
Antibodies are part of the body’s immune system An antibody is an immunoglobulin molecule that has a specific amino acid sequence that causes it to interact only with the antigen that induced its synthesis or with an antigen closely related to it in an immune response. Antibodies are classified according to their mode of action as agglutinins, bacteriolysins, hemolysins, opsonins, precipitins, etc.
Antibody, monoclonal
Antibody molecules that have a single binding site. Because of this specificity, monoclonal antibodies react only with the antigen that spawned their production, and none other.
Antibody, polyclonal
An antibody that is produced by several clones of B-lymphocytes and that reacts to different antigens.
A medicine that prevents or relieves nausea and vomiting and is often used before, during, and sometimes after chemotherapy or radiotherapy.
Any substance capable of inducing a specific immune response and of reacting with the products of that response. They may be foreign proteins, toxins, bacteria, or viruses.
The capacity of a molecule to interact with an immune-recognition molecule, such as an antibody, and therefore capable of inducing a specific immune response. Also called Immunogenicity.
Antigens, CD
Differentiation antigens residing on human leukocytes (white blood cells). CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens. The subpopulations of antigens are also known by the same CD designation.
Antigens, differentiation
Antigens expressed primarily on the membranes of living cells during sequential stages of maturation and differentiation. As immunologic markers, they have high organ and tissue specificity and are useful as probes in studies of normal cell development as well as neoplastic transformation.
Antigens, neoplasm
Protein, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. It is not clear whether there are antigens that are unique to tumors.
Anticancer drugs that interfere with the process of DNA production, thus preventing cell division.
Antineoplastic agents
Drugs that fight cancer. They can be antihormonal or chemotherapeutic.
A substance that prevents or delays the degradation and release of by-products of a chemical reaction that produces a particular type of oxygen that is damaging to tissue.
The strand of a double-stranded DNA that is complementary to the sense strand.
A diffuse, highly unpleasant, often vague feeling of apprehension, accompanied by sensations such as pounding of the heart and sweating. There is an associated anticipation of future misfortune or danger, either external or internal. It can be associated with depression. There are medications to effectively treat this condition.
One of the two mechanisms by which cell death occurs; the other is the pathological process of necrosis. Apoptosis, also known as programmed cell death, is the mechanism responsible for the physiological destruction of cells and appears to be genetically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA (DNA fragmentation) at intenucleosomal sites. This mode of cell death serve to destroy abnormal cells and to act as a balance to mitosis in regulating the size of tissues. Cancer has been characterized as a mismatch between mitosis and apoptosis.
The circular field of dark-colored skin surrounding the breast nipple.
Removal of fluid containing the cells of interest from tissue by inserting a needle and suctioning fluid into a syringe. Sometimes a fluid is injected prior to the suctioning to increase the number of cells collected.
The determination of the amount, purity, or potency of a substance.
Assay, antitumor
Methods of investigating the effectiveness of anticancer cytotoxic drug screening drugs and biologic inhibitors. These include in vitro cell-kill models, cytostatic dye exclusion test, and in vivo measurement of tumor growth parameters in laboratory animals. It is not used clinically because of its uncertain relationship to tumor activity in human beings.
Assay, biological
A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes quantification of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.
Assay, tumor stem cell
A cytologic technique for measuring the functional capacity of tumor stem cells by assaying their activity. It is used primarily for the in vitro testing of antineoplastic agents.
Without obvious (clinical) signs or symptoms of the disease. Early stage cancers are often asymptomatic.
The smallest particle of an element that can exist either alone or in combination with other atoms (compound, as in a chemical).
Decrease in size of cells, fibers, tissues, organs, and bodily parts. Occurs with aging, reduction in blood supply, or following malnutrition, prolonged immobilization, or denervation (loss of the nerve to a tissue).
Abnormal histological or cytological changes in epithelial cells.
Atypia, ductal
An increased number of breast ductal epithelial cells that show some but not all the characteristics of ductal carcinoma in situ. Ductal atypia is associated with an increased risk of developing breast cancer.
Atypical cells
Not usual cells. They can be normal cell variation or abnormal cells. Cancer cells are always atypical.
Secretion of a substance from cells that stimulates the secretion of substances from the same cells.
A condition in which the body produces an immune response against its own tissue.
Donor tissue (can be blood or components of the blood) that is obtained from a person who is also the recipient of the tissue.
Autologous transplant
A transplantation of tissue from one person to the same person.
A technique that uses x-ray film to visualize radioactively labeled molecules or fragments of molecules. It can be used to analyze the length and number of DNA fragments after they are separated by gel electrophoresis.
Autosomal dominant
A gene whose expression is the same whether the individual has one of the pair or both the pair of genes for that trait. If the individual has two different genes for that trait, it is the gene that is expressed. A parent has a 50% chance of passing on an autosomal dominant disease to each child.
Any chromosome other than the sex-determining X and Y chromosomes. Each human cells contain 22 pairs of autosomes and one pair of sex chromosomes for a total of 23 pairs of genes (46 genes).
Autosomal dominant
A gene that is always expressed.
Autosomal recessive
A gene that is only expressed if the individual has both of the same gene.
Under the arm, the armpit.
Axillary dissection
Surgical removal of the axillary contents, usually the lymph nodes. The procedure was performed in conjunction with a modified radial mastectomy but it was occasionally an independent procedure. Axillary dissection has been substantially replaced by the sentinel node biopsy. The extent of the axillary dissection is described in terms of levels. Level 1 is the removal of the axillary contents up to the inferior border of the pectoralis minor muscle. Level 2 is the removal of the axillary contents up to the superior border of the pectoralis minor muscle. Level 3 is the removal of the axillary contents up to the apex of the axilla.
Axillary lymph nodes
The lymph nodes in the axilla that are removed and examined during the surgical removal of breast cancer in order to determine if the cancer has spread from the breast to another site. Cancer spreading to the axillary lymph nodes is a poor prognostic sign.


See Bone marrow transplant.
See Benign prostatic hypertrophy.
B cells are the cells primarily responsible for humoral immunity and they are the precursors of antibody-producing cells (plasma cells). B cell maturation occurs primarily in the bone marrow in mammals. B cells are characterized by the presence of surface immunoglobulin, IgM or IgD, which constitutes the B cell antigen receptors. When stimulated by antigen, a process that requires the cooperation of helper T cells and macrophages, B cells proliferate and differentiate into plasma cells and memory B cells. The entire clone of cells descended from a single activated B cell produces immunoglobulins having the same antigen combining site as that in the antigen receptors of the original cell; thus all of the antibody produced and all of the memory cells are specific for the antigen that induced their formation. See also T-lymphocytes.
Familial breast and ovarian cancer susceptibility genes located on human chromosome 17q12-21 (BRCA1) and human chromosome 13 (BRCA2). One or both are mutated in a subset of early-onset inherited breast and ovarian cancers and they are associated with the development and progression of these cancers. The mutated forms of these genes also places women who possess them at greater risk of a contralateral breast cancer and of death due to breast cancer.
Breast self-examination.
A specific antibody that, together with other substances, is capable of causing the dissolution of a homologous bacterium.
A virus that lyses (destroys) bacteria.
Basal ganglia
Specific areas of gray matter in the brain (cerebral hemisphere).
A chemical substance with a pH more than 7.0 (also know as a alkaline substance). See also Acid.
Base pairs
The two complementary (one on each DNA strand) molecules held together to form double-stranded DNA Two strands of DNA are held together in the shape of a double helix by the bonds between their base pairs.
Benign prostatic hypertrophy
An increase in the size of the prostate caused by an increase in the size of the cells (contrasts with hyperplasia which is an increase in the number of cells). Not directly related to prostate cancer but both BPH and prostate cancer cause a rise in a man’s PSA. This is why an elevated PSA does not always, or even most of the time, mean that prostate cancer is present.
Benign tumor
An abnormal growth that is not cancerous and does not spread to other parts of the body.
A term used in statistics/epidemiology to denote a deviation of the results or inferences from the truth. It is difficult to detect bias. One way to test for certain types of bias is to perform a validation study (where the results or inferences are tested in a new population to observe if they are confirmed). Bias can result from several sources including systematic variations in measurement from the true value (systematic error), flaws in study design; deviation of inferences, interpretations, or analyses based on flawed data or data collection. Bias is a scientific term and is unrelated to its meaning ordinary discourse.
Both sides of the body. For example, bilateral breast cancer is cancer that occurs in both breasts.
The quantitative determination of the potency of a substance through the measurement of its effects on tissues, cells, living experimental animals, or humans.
Biological response modifiers
Biological or synthetic agents that are capable of eliciting specific and/or nonspecific effects on immune responsiveness, thereby leading to an improvement in overall health of the patient. These agents can be further subcategorized into those that facilitate a normal immune response, those that stimulate the immune response, those that are capable of inducing noncytotoxic immunosuppression, and those that increase the ability of the host to tolerate damage by the cytotoxic modalities of the treatment.
Biological therapy
Biological therapy attempts to get the body to fight cancer by using materials that are made by the body or made in a laboratory to boost, direct, or restore the body's natural defenses against disease. Biological therapy is sometimes called biological response modifier therapy, immunotherapy, or biotherapy.
The study of living things, organisms, their structure, development, and function.
A biological entity, usually a gene, protein, or compound that is directly related to the disease process. It is usually used to infer whether a therapy was successful before the clinical outcome can be expected to occur. A change in the biomarker, e.g., its reduction or elimination, suggests that the disease has been reduced or eliminated. For example, a lowering of the PSA after treatment suggests that the treatment was successful. Here the PSA is acting as a biomarker. See also surrogate outcome.
The removal of a sample of tissue, which is then examined under a microscope by a Pathologist. When a sample of a tumor is removed and examined, the procedure is called incisional biopsy; when the whole mass is removed and examined, it is called an excisional biopsy. Removing tissue or fluid with a needle for microscopic examination is called a needle biopsy or needle aspiration.
Blinded study
Blinding usually occurs in the context of a randomized clinical trail. A single blinded study is one in which the subjects are not told whether they receiving the control or the treatment. A double blinded study is one in which neither the subjects nor the experimenters know who is receiving the treatment. The problem is that many treatments have side effects so that both the subjects and the experimenters know who is receiving the treatment. When the persons analyzing the study do not know, then the study is called masked. When neither the subject, experimenters, nor the statisticians know who is receiving the treatment the study is triple blinded.
Blood count
See Complete blood count
General term for the transfer of protein, RNA, or DNA from a gel to a paper-like membrane by capillary action or an electric field, showing its spatial arrangement.
Body image
The individual's conception of and feelings about his or her body including its overall integrity, its physical characteristics, such as form, size and shape, and its conformity to societal values and norms. Self-esteem, psychosocial functioning, and sexuality are intimately linked to body image. Cancer therapy can be disfiguring, resulting in body image issues that need to be addressed.
Bone marrow
The soft tissue filling the inside of bones. Bone marrow exists as two types, yellow and red. Yellow marrow is found in large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes (i.e., red blood cells) and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers, with the frame being filled with marrow cells.
Bone marrow biopsy
A procedure in which a large needle is inserted into the center of a bone, usually of the hip, and a small amount of bone marrow is removed (drawn by vacuum pressure into a tube) for microscopic examination.
Bone scan
The injection of a trace amount of radioactive substance into the bloodstream that goes to areas of inflammation to see if cancer has spread to the bones.
Insertion of radioactive pellets in the tissue in the area of the cancer to destroy all the tissue in the area including the cancer tissue.
Breast conserving surgery
Procedure in which only that part of the breast that contains the cancer and some surrounding normal tissue is removed, the entire breast is not removed. Also known as a lumpectomy.
Breast implants
Used for cosmetic reasons a and for the reconstruction of breasts after mastectomy. Implants are filled with either silicone gel or saline. The silicone-filled implants are a silicone rubber envelope filled with soft, silicone gel that feels like very thick jelly. The envelope may have either a smooth or textured surface. Saline-filled implants are silicone rubber envelopes filled with sterile saltwater (saline solution). Most women prefer the silicone implants. Although a substantial proportion of the implants leak fluid over time, no credible scientific evidence has been presented to prove that the lost fluid causes disease.
Breast self-exam
A procedure used by a woman to manually examine her own breasts thoroughly once a month to detect any changes or suspicious lumps. Exams should be conducted at the end of the menstrual period or 7 days after the start of the period and be performed at the same time each month. There is insufficient evidence to suggest that breast self-examination saves lives.
Breast sharing
A method of breast reconstruction in which some of the tissue from the opposite breast is used to reconstruct the surgically altered breast.


Three of a number of lymphocyte surface proteins (markers) that promote the activities of T cells.
See Computed axial tomography.
See Computed axial tomography.
Severe, generalized weakness, malnutrition, and emaciation. Can be a side-effect of chemotherapy and a direct effect of cancer itself.
Small calcium deposits in breast tissue that can be seen on a mammogram. Calcium is deposited in tissue as a result of cell death and can occur with either benign or malignant changes. See: microcalcifications.
An uncontrolled increase the number of cells; cell proliferation that consistently exceeds the rate of cell death. See also: carcinoma, neoplasm, tumor.
Serum glycoprotein secreted into the gastrointestinal epithelia. CEA Antigen (CEA) occurs normally in feces pancreaticobiliary secretions, and in the plasma in a diverse group of neoplastic and non-neoplastic conditions. The primary use of CEA is in monitoring response to treatment of i colorectal cancer. CEA and other members of the CEA family appear to mediate intercellular adhesion.
Any substance that can initiate or promote the development of cancer. For example, tobacco and asbestos is a known carcinogens.
A name for epithelial cell neoplasms. A malignant growth made up of epithelial cells that infiltrates through the basement membrane into the surrounding tissues and which may give rise to cell growth in other areas of the body (metastases). Many solid tumors are carcinomas.
Carcinoma, infiltrating
An invasive (infiltrating) carcinoma of the breast. This carcinoma, in duct which no special histological feature is recognized, is designated Not Otherwise Specified (NOS), and is by far the most common ductal tumor, accounting for almost 70 percent of breast cancers. It is - characterized by stony hardness upon palpation and commonly metastasizes to the axillary lymph nodes. Its prognosis is the poorest of the various ductal types.
Carcinoma in situ
The abnormal cells are confined to the epithelium of origin, without invasion of the basement membrane. Also called ductal carcinoma in situ.
Carcinoma in situ, intraductal
A noninvasive (noninfiltrating) carcinoma of the breast characterized by a proliferation of malignant epithelial cells confined to the mammary ducts or lobules, without light-microscopy evidence of invasion through the basement membrane into the surrounding stroma. It may form palpable tumors. Its existence places a woman at increased risk of invasive disease. Also called ductal carcinoma in situ (DCIS).
Carcinoma in situ, lobular
An uncommon, noninvasive (nonfiltrating) carcinoma of the breast. It does not form palpable tumor and is usually an incidental finding. Its existence places a woman at an increased risk of invasive disease. Also called lobular carcinoma in situ (LCIS).
A person who has a recessive mutated gene and its normal allele. Carriers do not usually develop a disease but can pass the mutated gene on to their children.
Carrier testing
Testing to identify individuals who carry disease-causing recessive genes that could be inherited by their children. Carrier testing is designed for healthy people who have no symptoms of disease but who are at risk because of family history.
Case-control study
A type of epidemiologic study that compares persons with a disease - (cases) to persons without the same disease (controls) on the basis of their past exposure to a suspected risk factor. Cases and controls are matched to resemble each other in sex and age. Same as a retrospective study.
The surgical removal or chemical blockade of the gonadal organs (ovaries or testes) which lowers the hormone levels to close to zero. Usually used for hormone-responsive tumors (breast, prostate).
Increase in the rate of chemical reaction caused by a substance that is itself unchanged.
To stimulate a chemical reaction.
Categorical Variable
A variable that is divided into categories. Categories can be names or can be mutually exclusive ranges of values.
Catheterization (urethral)
The insertion via the urethra of a tubular, flexible instrument - (catheter) into the bladder to allow for the removal of urine.Caudal Located toward the tailor cauda.
The relating of causes to the effects they produce. Causes are termed necessary when they must always precede an effect and sufficient when they initiate or produce an effect. Any of several factors may be associated with the potential disease causation or outcome, including predisposing factors, enabling factors, precipitating factors, reinforcing factors, and risk factors.
Small, watery membrane-bound compartment filled with chemicals; the basic unit of any living organism.
Cell Line
Cells from a person or animal that can be grown in a culture dish (in vitro). These cells can be either normal or cancerous.
Related to or consisting of cells.
Infection occurring in soft tissues. After mastectomy, because of the removal of lymph nodes, the risk for cellulitis in the arm increases. Symptoms are pain, swelling, and warmth.
The process of rotating a mixture or substance at high speeds in order - to separate the lighter and heavier components of the substance.
See HER2-neu
Chemical Base
An essential building block. DNA contains four complementary bases-adenine paired with thymine and cytosine paired with guanine. In RNA, thymine is replaced by uracil. Chemoprevention or Administration of a chemical to prevent the development or Chemoprophylaxis progression of a disease.
Chemotherapy Drug treatment to kill cancer cells.
Chemotherapy may be taken by mouth or it may be put into the body by a needle into a vein, artery, or muscle. Chemotherapy is considered a systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells anywhere in the body.
An organism composed of two genetically distinct types of cells.
Chi-square test
A method for determining the probability of one population having occurred by chance and for comparing two or more populations to determine the probability that they are samples of one underlying population (not statistically different at the 0.05 level) or are really different populations (less than one out of twenty times would we say that the two populations are different when they really are not different). The test is based on the chi-square distribution which assumes that the population is normal, in other words, that the variables are independent and have normal distributions, each with mean 0 and with variance 1.00 and that the variables are discrete rather than continuous. The chi-square probability distribution is the sum of the squares of a number of independent normal variables and it is closely related the Gamma distribution. Also known as the chi-squared test.
Resembling acetylcholine in pharmacological action; stimulated by or releasing acetylcholine or a related compound.
Cholinergic Agents
Any drug used for its actions on cholinergic systems. Included here are agonists and antagonists, drugs that affect the life cycle of acetylcholine, and drugs that affect the survival of cholinergic - neurons. The term is sometimes still used in the narrower sense of muscarinic agonists, although some modem texts discourage that usage.
Easily stainable DNA attached to a protein in the cell nucleus-the carrier of genes in inheritance.
Lacking sex chromatin and characteristic of the nuclei of cells of normal males.
Containing sex chromatin (Barr body) and characteristic of the nuclei of cells of normal females.
A method of chemical analysis in which the solution to be analyzed is poured into an absorbent-containing vertical glass tube, the different solutes moving through the absorption column at different velocities, and producing bands of color at different levels of the column.
Mapping Any method used for determining the location of and relative distances between genes on a chromosome.
A structure in the nucleus of all human cells that contains a linear strand of DNA. Each species has a characteristic number of chromosomes. Humans have 46 chromosomes (23 pairs), including the pair of two sex chromosomes (XX for women and XY for men). The person’s genotype in conjunction with the environment, determines what the person looks like (phenotype).
The collarbone.
Clinically undetectable disease
The absence of signs and symptoms of the disease. The inability of the physical examination or of any test to detect the existence of the disease.
Clinical trial
A clinical trial is an experiment to determine if an intervention works in a particular group of patients at risk for a specific disease or with a specific disease. The intervention can be a test, device, procedure, or drug used for prevention, treatment, or palliation. For example, a drug can be given to patients and the patients can be followed to see how well they do. But it cannot be known if the drug had any effect without a comparison group that did not receive the drug. This allows intervention group outcome to be compared to the control group outcome. The control group can be historical in which case it is a no-treatment group. Other types of control groups can be groups that are recruited at the same time as the intervention group and the patients in the control group can receive either no treatment, a placebo treatment, or a drug with know efficacy. A major problem with this approach is that the two groups, the intervention group and the control group, may be different in a way that affects the outcome of the group. For example, if only the less sick patients are given the drug, then as the two groups were followed over time the intervention group would do better than the control group and we would conclude the intervention works, even if it did not really work because there was a bias in the two groups. This problem is solved by randomizing patients to either the intervention group or the control group. The idea is that if we randomly select patients for each group there will be no important differences between the two groups, if there are important unknown differences they are called “unmeasured covariates”. Therefore, any difference in outcome between the two groups can be attributed to the intervention. For randomization to be successful there must be enough patients in each group so that all the important outcome factors are equally distributed between the two groups. If there are too few patients in each group randomization does not guarantee that the two groups will be the same. Notice that the clinical trial is not usually used to provide information about individual patients, it provides information about groups of patients. In the study the groups of patients are defined by the study “entry criteria”, the rules for who can participate in the study. One problem with the clinical trial design is that the results of the study may not apply to patients who do not meet the entry criteria, this is known as the study results not being “generalizable”. Another problem is that because the study groups are so homogeneous, the patients are very similar within each group, small differences in entry criteria or in the outcomes can have major effects on the results. This is why two randomized clinical trials that seem to be the same can produce different results.
A group of identical genes, cells, or organisms derived from a single ancestor.
The process of making genetically identical copies.
A term generally used to mean a group of similar subjects born at the same time or having some other similar feature, and followed in a study over time.
Cohort Effect
Variation in health status arising from different causal factors to which each birth cohort in a population is exposed as environment and society change.
Cohort Studies
Prospective investigation of the factors that might cause a disorder in ~ which a cohort of individuals, who do not have evidence of but who are exposed to the putative cause, are compared with a concurrent cohort who are also free of the disorder but not exposed to the putative cause. Both cohorts are then followed to compare the - incidence of the outcome of interest (e.g., disorder). Also called longitudinal and prospective study.
A state of matter in which tiny or microscopic particles are dispersed and are unable to pass through cell membranes.
Treatment consisting of the use of two or more chemicals to achieve Chemotherapy maximum destruction of tumor cells.
Combined Modality
The treatment of a disease or condition by several different means Therapy simultaneously or sequentially. Chemoimmunotherapy, radioimmunotherapy, chemoradiotherapy, cryochemotherapy, and salvage therapy are seen most frequently, but their combinations with each other and surgery are also used.
Carcinoma in situ A high-grade type of in situ breast carcinoma with large, poorly differentiated cells and central necrosis; also known as large-cell in situ carcinoma.
Complementary DNA
DNA synthesized through viral reverse transcriptase that is (cDNA) complementary to RNA.
Complete blood count
A laboratory test to determine the number of red blood cells, white (CBC) blood cells, platelets, hemoglobin, and other components of a blood sample.
Complete Local Excision
The complete excision of an entire tumor mass, including a margin of (CLE) normal tissue that surrounds it, confirmed by histological examination of the margins.
Computed axial tomography
An imaging method in which radiation is directed at the body and the radiation is detected, and the anatomic features of the body reconstructed, by axial tomography. Abbrev: CT, CAT scan.
Confounding Factors
Factors that can influence the cause or prevention of the outcome of interest; these are not intermediate variables. They give rise to situations in which the effects of two or more causes are not separated, or the contribution of causal factors cannot be separated, or the measure of the effect of exposure or risk is distorted because of its association with other factors influencing the outcome of the study.
Existing at, and usually before, birth; referring to conditions that are present at birth, regardless of causation.
Contig Maps
Types of physical DNA maps that consist of overlapping segments of DNA (contigs) that taken together completely represent that section of the genome. See also Physical maps.
Continuous variable
A variable that has a potentially infinite number of possible values along a continuum.
The other side. In breast cancer, the other breast.
Control Group
In an experimental study, the group of subjects who do not receive the intervention or experimental treatment. The effects of the treatment on the experimental group are compared to the effects of no treatment on the control group.
Cooper's Ligaments
Flexible bands of tissue that pass from the chest muscle between the lobes of the breasts, providing shape and support for the breasts.
Coping Strategies
Mental strategies or behaviors employed to maximize functioning and - reduce or eliminate psychological distress in response to stressful situations. Coping strategies may be influenced by personality style and by the specific situation and may change over time.
Core Biopsy
Removal (with a large needle) of a piece of a tumor or lump. The piece is then sent to the laboratory to determine if the tumor is benign or malignant.
Correlation (coefficient)
The degree to which variables change in unison. The correlation coefficient indicates the degree to which two variables have a linear relationship and can vary from +1 (perfect positive linear relationship) to -1 (perfect negative linear relationship).
The art of increasing and preserving beauty. It is generally accepted that one goal of conservative treatment is to retain a breast with an appearance as close to normal as is compatible with effective treatment.
Crossing Over
phenomenon, also know as recombination, that sometimes occurs during the formation of sperm and egg cells (meiosis). A pair of chromosomes (one from the mother and the other from the father) break and trade segments with one another. Cross-over An experimental study design in which subjects alternatively receive each of the treatments being tested.
Freezing tissue, which kills the tissue along with any cancerous cells .(usually done using liquid nitrogen).
In cancer, unlike most other diseases, it does not mean that the disease has been completely destroyed. Rather, it means being free of detectable cancer for at least five years.
One in a series of regular intervals during which chemotherapy is administered. A cycle commences with the administration of the chemotherapy and ends when the nadir has passed and the white blood and platelet counts have returned to pretreatment values. The - next cycle of chemotherapy is then given.
The use of a hollow metal tube (cystoscope) for examining the bladder and urethra.
Any of several intracellular enzymes that function to transport electrons or hydrogen to molecular oxygen.
Nonantibody proteins secreted by inflammatory leukocytes and some nonleukocytic cells that act as intercellular mediators. They differ lfrom classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. Cytokines generally act locally.
The microscopic study of individual cells that have been sloughed off, cut out, or scraped off organs to be examined for signs of cancer. Cytoplasm The cellular substance outside the nucleus, in which the cell's organelles are suspended.
Some agent that can cause the death of cancer cells. It usually refers to chemotherapeutic drugs.


See Ductal carcinoma in situ.
See Deoxyribonucleic acid.
See Diaphanography.
See Digital rectal examination.
Thread-like or tree branch-like extensions, such as the receptive surface of a new cell that branches off from the cell body.
Dendritic cells
Cells that are branched like a tree and convey antigens.
Failure to acknowledge some aspect of external reality that would be apparent to others; an involuntary reaction (as opposed to lying) that aims to avoid anxiety.
The loss of the nerve to a tissue. Usually results in atrophy of the tissue.
Deoxyribonucleic acid
One of two nucleic acids (the other is RNA) found in the nucleus of allcells. DNA contains the genetic information on cell growth, division, and function. It is the blueprint of life.
Deoxyribonucleic acid ploidy
see Ploidy, deoxyribonucleic.
Deoxyribonucleic acid polymerase (DNA polymerase)
Enzyme involved in the synthesis of DNA, using one strand of DNA Polymerase as a template for the production of a new, second strand. Retroviruses possess a unique DNA polymerase, reverse transcriptase, that uses an RNA template.
Deoxyribonucleic acid repair (DNA repair)
Certain genes that are part of a DNA repair pathway. When they are altered they permit mutations to pile up throughout the DNA.
Deoxyribonucleic acid sequencing (DNA sequencing)
Determining the exact order of the base pairs in a segment of DNA.
Dependent variable
An outcome variable that researchers seek to explain or account for by the influence of independent variable(s).
A pervasive and sustained lowering of mood, often associated with tearfulness, guilt, or irritability. Other features include loss of interest in activities, lowered energy levels, impaired concentration, and disturbance of sleep and/or appetite.
The discovery of an abnormality in an asymptomatic or symptomatic person.
The process of detecting and identifying a disease by characteristic signs, symptoms, and laboratory findings. The diagnosis of cancer is made by taking a biopsy of the abnormal tissue and the Pathologist examining the tissue under a microscope for cancerous cells.
To separate a substance from a solution by means of their unequal diffusion through semipermeable membranes.
A noninvasive procedure that uses ordinary light, passed through tissue, as an investigative tool to detect masses in an organ; also called transillumination. The utility of this approach is under investigation.
The degree to which a tumor resembles normal tissue. In general, the closer the resemblance, the better the prognosis. Well-differentiated tumors closely resemble normal tissue.
Digital rectal exam
A physician inserts a finger into the rectum and manually examines the rectum and, in the male, prostate gland. It has a not an adequate prostate screening test because of its poor ability to detect cancer.
A compound produced when two similar molecules combine without losing atoms.
Process of skin pulling in toward breast tissue, often referred to as retraction.
The characteristic of having two sets of 23 chromosomes in a cell. This is a normal condition of most human cells.
Disease progression
See Progression.
Disease-free survival
A period after successful treatment during which the patient is alive and free of clinically detectable disease.
A discrete portion of a protein with its own biological properties. The combination of the domains in a single protein determines its overall function.
Toward the back, opposite from the abdomen.
A relationship in which a change in the amount, duration, or intensity relationship of an exposure (including exposure to drug therapy) is associated with an increase or decrease in an outcome or risk of an outcome.
Double blinded study
See Blinded study.
Doubling time
The time required for a group of cells to double in number. For example, breast cancer cells doubles in size every 23 to 209 days. It would take one cell, doubling every 100 days, 8 to 10 years to reach one centimeter (3/8 inch).
Ductal carcinoma
An invasive cancer that begins inside the ducts of the breast. It is the most common type of breast cancer, accounting for 80% of all new cases.
Ductal carcinoma in situ
A noninvasive cancer that can progress to invasive breast cancer. It is sometimes referred to as a precancerous lesion. Most people who have in situ cancers have good prognoses. (DCIS)
Ductal papillomas
Small noncancerous finger-like growths in the mammary ducts that may cause a bloody discharge from the nipple; commonly found in women 45 to 50 years of age.
An abnormal growth of cells that have some of the features of carcinoma cells but that have insufficient changes to warrant a diagnosis of carcinoma. This is a pathological term and should be differentiated from the radiological term dysplasia, which refers to an abnormal radiological appearance, usually due to fibrocystic disease. See also Atypia.


Cadherins are protein molecules located in the cell membrane that are necessary for cell-cell attachment. E-cadherin is a cell adhesion receptor expressed in epithelial cells including breast and prostate.
The external layer of the embryo that forms into tissues such as nails, hair, nerves, and mucous membranes.
Excess fluid found in the body or in a body part that is outside of the vascular system and outside cells; sufferers describe the condition as feeling swollen or puffy.
The extent to which, under ideal conditions, an intervention, procedure, or regimen produces a benefit.
The smallest particle of negative electricity. Electrons have the useful property of finite penetration of tissue as opposed to the exponential absorption that occurs with x-rays.
The separation of a mixture by suspending it in a medium such as gel, paper, or liquid, and then applying an electric field. The components migrate along the field at different speeds according to their molecular characteristics. Elution In chemistry, the separation of material by washing, generally to separate heavier constituents that settle out in solution from the lighter ones.
Endocrine Manipulation
Treating breast cancer by changing the hormonal balance of the body - to prevent hormone-dependent cancer cells from multiplying.
Produced from within.
Situated within the mucous membrane lining of the uterus. Endonuclease A nuclease (enzyme) that splits bonds.
A structure that encloses or covers. A nuclear envelope surrounds the nuclear material of a cell; a viral envelope is the outer structure that encloses the nucleocapsid of some viruses.
Any protein that acts as a catalyst, increasing the rate of a chemical reaction. Enzyme names often end with the SuffIX ase.
A laboratory method used to detect the presence of antibodies and immunosorbent assay antigens.(ELISA)
Study of the determinants, distribution, and outcomes of health - conditions, including diseases, within a population.
The outermost layer of the skin.
Cadherins are protein molecules located in the cell membrane that are necessary for cell-cell attachment. E-cadherin is a cell adhesion receptor expressed in epithelial cells including breast and prostate.
In a complex antigenic molecule (having the properties of an antigen), the simplest form of an antigenic determinant.
Redness of the skin. The earliest sign of radiation reaction, it usually - occurs after a conventionally fractionated dose of about 40 Gray has been delivered.
One of the elements found in peripheral blood; also called red blood cells or red corpuscles. Normally, in the human, the mature form is a non-nucleated, yellowish, biconcave disk, adapted, by virtue of its configuration and its hemoglobin content, to transport oxygen.
A form of estrogen synthesized mainly in the ovary, but also in the placenta and testes.
hormone (secreted by the ovaries) that is essential for menstruation, reproduction, and the development of secondary sex - characteristics, such as breasts.
Estrogen Receptor (ER)
In intracellular receptor protein that binds estrogens and anti-estrogens and then binds to DNA and alters the expression of specific - genes. It is an indicator of responsiveness to hormonal therapies. I I High ER expression is associated with a good prognosis and with a positive response to hormonal therapy.
Estrogen Receptor Assay
A test of cancerous tissue to determine whether it is hormone-(ERA) dependent and thus may respond to hormonal therapy. The test will - reveal if the cancer is ER positive or negative.
Cause of disease or the study of causes of disease. The study designs most typically used are longitudinal, cohort, or prospective studies, - and retrospective or case control studies.
An organism whose cells have true nuclei bounded by nuclear - membranes and contain chromosomes that divide by mitosis. Humans are eukaryotes.
Eukaryotic Cells
A cell with a true nucleus.
Excisional Biopsy
Surgical removal of a lump or suspicious tissue by removal of the entire tissue.
Denved or developed from external sources.
The protein-coding sequence of a gene.
Extensive Intraductal
EIC is generally said to exist when 25 percent or more of the primary - Carcinoma (EIC) invasive tumor mass consists of ductal carcinoma in situ (DCIS) and when areas of DCIS coexist in the adjacent breast tissue. EIC is a ' I predictor for high relapse rates following wide local excision and radiotherapy.
False Negative Reactions
Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease.
One of the elements found in peripheral blood; also called red blood i cells or red corpuscles. Normally, in the human, the mature form is a non-nucleated, yellowish, biconcave disk, adapted, by virtue of its configuration and its hemoglobin content, to transport oxygen.
A form of estrogen synthesized mainly in the ovary, but also in the placenta and testes.
A hormone (secreted by the ovaries) that is essential for menstruation, reproduction, and the development of secondary sex - characteristics, such as breasts.
Receptor (ER) An intracellular receptor protein that binds estrogens and anti-estrogens and then binds to DNA and alters the expression of specific genes. It is an indicator of responsiveness to hormonal therapies. High ER expression is associated with a good prognosis and with a positive response to hormonal therapy.
Receptor Assay A test of cancerous tissue to determine whether it is hormone- (ERA) dependent and thus may respond to hormonal therapy. The test will - reveal if the cancer is ER positive or negative.
Ethylenimine derivatives
A type of chemotherapy, an alkylating agent, includes thiotepa.
Cause of disease or the study of causes of disease. The study designs most typically used are longitudinal, cohort, or prospective studies, and retrospective or case control studies.
An organism whose cells have true nuclei bounded by nuclear - membranes and contain chromosomes that divide by mitosis. Humans are eukaryotes.
Eukaryotic Cells
A cell with a true nucleus.
Evidence of effect
That there is evidence for the existence of an effect, the effect was significantly greater than what would be expected by chance. This contrasts with “evidence of no effect” which means that the study had sufficient power to detect an effect if there truly was one and did not find an effect. “No evidence of an effect” means that no effect was detected but we cannot be sure that there truly was no effect because the study was underpowered.
Excisional Biopsy
Surgical removal of a lump or suspicious tissue by removal of the entire tissue.
Derived or developed from external sources.
The protein-coding sequence of a gene.
Extensive Intraductal
EIC is generally said to exist when 25 percent or more of the primary - Carcinoma (EIC) invasive tumor mass consists of ductal carcinoma in situ (DCIS) and when areas of DCIS coexist in the adjacent breast tissue. EIC is a predictor for high relapse rates following wide local excision and radiotherapy.


False Negative Reactions
Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease.
False Positive Reactions
Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease.
Familial Adenomatous
An inherited condition in which hundreds of potentially cancerous Polyposis polyps develop in the colon and rectum.
Familial Breast Cancer
Breast cancer that occurs in first degree relatives. This occurrence implies an inherited predisposition to breast cancer, particularly when the disease occurs prior to menopause. The two best described syndromes of familial breast cancer are due to BRCAI gene mutations (with a possible concurrent predisposition to ovarian cancer) and gene mutations (Li-Fraumeni syndrome). Recently, a second gene, BRCA2, has been identified on chromosome 13. Familial breast cancers are thought to comprise fewer than 10 percent of all breast cancers.
Fat Necrosis Tumor
Destruction of fat cells due to trauma or injury; may cause a hard noncancerous lump.
A noncancerous, solid tumor in the breast; most commonly found in younger women.
A connective tissue cell that differentiates into fibrous tissue.
Fibrocystic Disease
A chronic disorder comprising three variants that range from lesions - Breast consisting primarily of an overgrowth of fibrous tissue to those characterized by dominance of the proliferation of the epithelial parenchyma to a form of dysplasia characterized by both stromal and epithelial hyperplasia, with the formation of cysts.
A tumor composed mainly of fibrous or connective tissue. Fibrosis The development of tissue that is composed of fibers.
Fine Needle Aspiration
Procedure to remove cells or fluid from tissues using a needle with an empty syringe. Cells or fluid are extracted by pulling back on the plunger.
Flow Cytometry
A technique for counting fluorescent-labeled cells or for separating selected populations of the cells for subsequent study; examines large numbers of cells and allows the separation of populations with, for ,- example, particular surface properties.
A synthetic anti androgen used in the palliative hormonal treatment of prostate cancer.
Founder Effect
The principle that. when a smaller subgroup of a larger population , establishes itself as a separate and isolated entity, its gene pool carries only a fraction of the genetic diversity of the parent I population. This may result in an increased frequency of certain diseases in the subgroup, especially those diseases known to be autosomal recessive.
False Positive Reactions
Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease.
Familial Adenomatous
An inherited condition in which hundreds of potentially cancerous Polyposis polyps develop in the colon and rectum.
Familial Breast Cancer
Breast cancer that occurs in first degree relatives. This occurrence implies an inherited predisposition to breast cancer, particularly when the disease occurs prior to menopause. The two best described syndromes of familial breast cancer are due to BRCA1 gene mutations (with a possible concurrent predisposition to ovarian cancer) and gene mutations (Li-Fraumeni syndrome). Recently, a second gene, BRCA2, has been identified on chromosome 13. Familial breast cancers are thought to comprise fewer than 10 percent of all breast cancers.
Fat Necrosis Tumor
Destruction of fat cells due to trauma or injury; may cause a hard noncancerous lump.
A noncancerous, solid tumor in the breast; most commonly found in younger women.
A connective tissue cell that differentiates into fibrous tissue.
Disease of A chronic disorder comprising three variants that range from lesions - Breast consisting primarily of an overgrowth of fibrous tissue to those characterized by dominance of the proliferation of the epithelial parenchyma to a form of dysplasia characterized by both stromal and epithelial hyperplasia, with the formation of cysts.
A tumor composed mainly of fibrous or connective tissue. Fibrosis The development of tissue that is composed of fibers.
Fine Needle Aspiration
Procedure to remove cells or fluid from tissues using a needle with an empty syringe. Cells or fluid are extracted by pulling back on the plunger.
Flow Cytometry
A technique for counting fluorescent-labeled cells or for separating selected populations of the cells for subsequent study; examines large numbers of cells and allows the separation of populations with, for example, particular surface properties.
A synthetic anti androgen used in the palliative hormonal treatment of prostate cancer.
Founder Effect
The principle that. when a smaller subgroup of a larger population establishes itself as a separate and isolated entity, its gene pool carries only a fraction of the genetic diversity of the parent I population. This may result in an increased frequency of certain L diseases in the subgroup, especially those diseases known to be autosomal recessive.
Free Flap Reconstruction
Soft tissue reconstruction in which the tissue (such as a muscle flap) is separated from its donor site, and a new blood supply to the tissue is established using microsurgical techniques.
Frozen Section
A technique in which a part of the biopsy tissue is frozen immediately, and a thin slice is then mounted on a microscope slide, enabling a pathologist to analyze it in just a few minutes for a preliminary diagnosis.
Frozen Shoulder
A severely restricted range of motion and pain occurring in the -, shoulder after surgery.
Functional Gene Tests
Biochemical assays for a specific protein, which indicate that a - specific gene is not merely present, but also active.
Slender, rod-shaped.


An energy-transferring enzyme.
A nonradioactive substance injected into the body to enhance visualization of abnormalities during magnetic resonance imaging (MRI).
Gamma Knife
A form of radiation therapy that uses a highly focused beam.Gene Segment of a DNA molecule that contains all information for synthesis of a product (e.g., RNA molecule). The biological unit of heredity, each gene has a specific position (locus) on the chromosome - map.
Gaussian distribution
Graphically it is a bell-shaped (symmetric and unimodal) curve where the x-axis is the range of the variable’s values (the ends of the distribution go to infinity in each direction) and the y-axis is the frequency of each values occurrence. The entire area under the curve represents the probability 1.00. The mean, median, and mode all have the same value. This shape is also called a Normal distribution.
Gene Amplification
A process of DNA duplication that results in a chromosome having - more than one copy of a gene or genes and that can lead to inappropriate gene activation. It is a common mechanism of activation of oncogenes such as erbB-2 and c-myc in breast cancer.
Gene Deletion
The total loss or absence of a gene.
Gene Expression
The process by which a gene's coded information is translated into the - structures present and operating in the cell (either proteins or RNAs).
Gene Mapping
Determining the relative positions of genes on a chromosome and the distance between them.
Gene Markers
Landmarks for a target gene either by detectable traits that are - inherited along with the gene, or distinctive segments of DNA.
Gene Testing
Examining a sample of blood or other body fluid or tissue for biochemical, chromosomal, or genetic markers that indicate the - presence or absence of genetic disease.
Gene Therapy
Treating disease by replacing, manipulating, or supplementing nonfunctional or abnormal genes.
Genetic Epidemiology
Study of the etiology, distribution, and control of diseases in groups of relatives and of inherited causes of disease in populations; includes studying the role of genetic factors and their interaction with environmental factors in development of disease in human populations.
Genetic Linkage Maps
DNA maps that assign relative chromosomal location to genetic landmarks-either genes for known traits or distinctive sequences of DNA-on the basis of how frequently they are both inherited. See also Physical maps.
Genetic Markers
A genetic polymorphism with a simple mode of inheritance occurring with different frequencies in different populations, and therefore useful in family studies, studies of the distribution of genes in populations, and linkage analysis.
Genetic Polymorphism
Co-occurrence in the same population of two or more genetically determined hereditary characteristics (i.e., phenotypes) in such proportions that the rarer one cannot be maintained by recurrent mutation.
The scientific study of heredity-how particular qualities or traits are - transmitted from parents to offspring.
All the genetic material in all the chromosomes of a particular organism.
Genome Maps
Charts that indicate the ordered arrangement of the genes and other DNA markers within the chromosomes.
The individual’s genetic make-up. Also, the gene alleles present at specific loci.
Germ Cells
The reproductive cells of the body, either egg or sperm cells, and their precursors.
Germline mutation
See Mutation, hereditary.
Gleason Grading
A system for describing the degree of severity of a prostate cancer - based on appearance of the cancer cells.
One of many compounds that consist of a protein-carbohydrate - (also called glucoprotein) complex. The most important are the mucins, mucoids, and amyloids.
Peptides that act on the pituitary to stimulate the synthesis and Hormones (GnRH) secretion of gonadotrophins and that also act on the brain, retina, sympathetic nervous system, and gonads.
Hormones, secreted from the pituitary gland, that stimulate growth of the gonads and secretion of sex hormones; include follicle stimulating hormone and luteinizing hormone.
Testes or ovaries.
The degree of differentiation of a cancer, which is related to the -., prognosis. Grade is assessed by a pathologist who examines cancer cells microscopically. A grade 1 carcinoma is well differentiated and associated with a good prognosis. A grade 2 carcinoma is moderately - differentiated and associated with an intermediate prognosis. A grade 3 carcinoma is poorly differentiated and associated with a poor prognosis.
Graft -versus- Host
Disease caused by the immune response of incompatible, Disease immunocompetent donor cells against the tissues of the immunoincompetent host, which can occur as a complication of bone - marrow transplantation when the recipient has a cellular immunodeficiency. Also called graft-versus-host reaction.
Gray (Gy)
The unit of radiation dosage. Doses used in curative cancer management usually vary from 45 to 65 gray. A centigray is 1/100 of a gray. Past unit was Rad.
The normal emotional response to loss, which may include a complex range of painful feelings such as sadness, anger, helplessness, guilt, and despair.
Growth Factors
Hormones that regulate the division of cells. Disturbances of growth factor production or of the response to growth factor are important in - neoplastic transformation.
Growth Substances
Signal molecules that are involved in the control of cell growth and differentiation.
A family of proteins that suppress tumors in certain cancers. GAPs Triphosphatase-activating are similar in structure to a part of neurofibromin. - Proteins (GAP)
Development of breast tissue in males.


See Human papilloma virus.
Surgeon in the late 19th and early 20th centuries who perfected the modified radical mastectomy. See Mastrectomy, radical.
Health status indicators
The measurement of the health status of a given population using a variety of indices, including morbidity, mortality, and available health resources.
Hematopoietic tissue
The site of production of erythrocytes (i.e., red blood cells) and granular leukocytes in the red bone marrow. It can be suppressed by drugs, infection, malnutrition, and radiation.
Blood in the urine.
A substance that frees hemoglobin from the red blood cells.
Hepatocyte growth factor
Mitogen shown to cause cell division in hepatocytes (liver cells).
Liver cells.
HER-2 neu
The amplification of the human epidermal growth factor receptor (HER) gene, a proto-oncogene, results in HER-2 receptor (protein) overexpression in ovarian and breast cancers. The anti-HER-2 monocolonal antibody Herceptin (Trastuzmab) is used in conjunction with paclitaxel to treat HER2-neu positive metastatic breast cancer. HER2 is also known as c-erbB2. There are a number of other growth factor receptors in the erbB family, including ErbBl/EGFR, ErbB3, and ErbB4.
An individual or organism in whom both the ovaries and testes are present, either as separate organs or combined in the same organ.
Derived from a different species; cellular elements occurring where they are not usually found.
Having different alleles for a given gene.
The area of science that deals with the minute (usually microscopic) structure, composition, and function of the tissues.
Histone proteins
Water-soluble proteins found in the cell nucleus that are associated with DNA in chromatin. Histone is found in urine in leukemia and febrile conditions.
Corresponding in structure. Transplantation in the same species (also known as allogenic transplantation).
A member of the same species, but different genotype, or having a similar structure or position.
Having identical alleles for a given gene.
Hormonal therapy
Treatment of cancer by alteration of the body’s hormonal balance. Treatments include tamoxifen for breast cancer and fanesteride for prostate cancer.
Chemicals secreted by various organs in the body that help regulate growth, metabolism, and reproduction. Some hormones are used as treatment for breast, ovarian, and prostate cancers.
Hormone dependent tumor
A hormone-dependent tumor regresses on removal of the hormonal stimulus, by surgery or pharmacological block.
Hormone receptor assay
A diagnostic test to determine whether cancer cells have receptor proteins for certain hormones and can therefore be treated with hormonal therapy.
Hormone-responsive tumors
Hormone-responsive tumors may regress when pharmacologic amounts of hormones are administered regardless of whether previous signs of hormone sensitivity were observed. The major hormone-responsive cancers include carcinomas of the breast, prostate, and endometrium; lymphomas; and certain leukemias.
Hormone sensitive tumor
Hormone -sensitive tumors may be hormone-dependent, hormone-responsive, or both.
Animal or plant that harbors or nourishes another organism, such as a parasite or other infectious organism.
Hot flashes
A sensation of heat and flushing that occurs suddenly. It is associated with menopause or the use of certain medications.
Human genome
The full collection of genes comprising a human being's genetic and physical characteristics.
Human Genome Project
An international research effort (led in the United States by the National Institutes of Health and the Department of Energy) to identify the DNA sequence of the human genome. Substantially completed by Celera Genomics in collaboration with the HGP in 1991. (Science 2001;291:1304-51. Nature 2001;409:860-921).
Human papilloma virus
A large group of more than 70 different viruses. Some strains cause common warts on the hands and feet, while other strains can be sexually transmitted and are responsible for genital warts. Human papilloma viruses can cause abnormal cells to grow in the cervix and certain strains (such as HPV-16 and HPV-18) are associated with an increased risk of developing cervical cancer.
Any fluid or semifluid part of the body.
Humoral antibody
An antibody found in solution in the lymph, plasma, or other fluid part of the body, as contrasted with antibody bound to the surface of a cell.
Humoral immunity
Immunity that is maintained by antibody molecules secreted by B lymphocytes and plasma cells that circulate freely through lymph, plasma, and other body fluids. Contrasts with cell-mediated immunity which is maintained by T lymphocutes.
An offspring (plant or animal) whose parents were of different species or different varieties of the same species.
Technique in which one strand of DNA or RNAis used to form hybrid strands from molecules with sufficiently similar, complementary sequences. Combinations can be DNA-DNA, DNA-RNA, or RNA-RNA.
An increase in the number of cells in an organ.
An increase in the size of the cells in an organ.
An insufficient amount of oxygen reaching bodily tissues to sustain the tissue.


An adverse event in a patient caused by a physician or other healthcare provider.
Immune System
Cellular and molecular components having the primary function of - distinguishing self from non-self and providing defense against foreign organisms or substances. The primary cellular components are lymphocytes and macrophages, and the primary molecular - components are antibodies and lymphokines.
Techniques for staining cells or tissues using antibodies to fight an - appropriate antigen.
The capacity of a molecule to elicit an immune response. See Antigenicity.
Immunoglobin (Ig)
The term used for antibodies that have specific antigen-binding . capacity. Antibodies can bind antigens and then mediate several other - activities or functions in the interaction with other cells and molecules of the immune system. The five different immunoglobin classes (isotypes) in humans are IgM, IgD, IgG, IgE, and IgA.
Application of antigen-antibody interactions to histochemical techniques (e.g., antibody labeled with a fluorescent dye).
Study of the body's mechanisms of resistance against disease or invasion by foreign substances; the ability of the body to fight a disease.
The prevention or diminution of the immune response, as by irradiation or by administration of antimetabolites, antilymphocyte serum, or specific antibody; called also immunodepression.
A treatment that stimulates the body's own defense mechanisms to - combat diseases such as cancer.
Active immunization where vaccine is administered for therapeutic or - preventive purposes. This can include administration of biological response modifiers such as interferons, interleukins, and colony stimulating factors in order to directly stimulate the immune system.
The inability to have or maintain an erection.
A biochemical phenomenon that determines for certain genes which - one of the pair of alleles, the mother's or the father's, will be active in that individual.
Errors of Inherited diseases resulting from alterations in genes that code for Metabolism enzymes.
Incidence (rate)
The rate of new cases of a disease or event in a specified population - during a specified time period.
Incident disease
Newly discovered disease. In screening denotes patients whose disease was detected after the initial screening. It contrasts prevalent cases, i.e., patients whose disease existed prior to the screening and were detected at the initial screening.
Incisional Biopsy
An incision into a tumor to remove a portion to determine whether it - is benign or malignant.
Incontinence (Urinary)
The inability to control urination.
Independent Variable
A variable under observation or being measured because of its hypothesized effect on the dependent variable.
An area of abnormal hardness.
Tissue death resulting from too little blood flow or oxygen. Infiltrating Cancer Cancer that has grown from the site in which it originated and into surrounding tissues.
Infiltrating Ductal Cell
A cancer that began in the mammary glands and has spread to areas Csircinoma outside the gland.
A localized protective response elicited by injury or destruction of tissues, which serves to destroy, dilute, or wall off both the injurious agent and the injured tissue. It is characterized in the acute form by the classical signs of pain, heat, redness, swelling, and loss of function. It involves a complex series of events, including dilation of arterioles, capillaries, and venules, with increased permeability and blood flow; exudation of fluids, including plasma proteins; and - leukocytic migration into the inflammatory focus.
Informed Consent
Voluntary authorization, given to the physician or an investigator, by - the patient, with full comprehension of the risks involved, for diagnostic or investigative procedures and medical and surgical treatment. In situ In place, localized and confined to one area; a very early stage of cancer.
In situ
The abnormal cells that have not invaded the basement membrane. See Carcinoma in situ.
Family of proteins that are located on the cell surface and that are involved in binding to components outside the cell.
A family of glycoproteins (produced in mammals) that prevent virus multiplication in cells. They are produced by immune cells after antigen stimulation.
Any of several compounds that are produced by lymphocytes or monocytes (white blood cells) that regulate the immune system.
Residing within the duct of the breast. Intraductal disease may be either benign or malignant.
Intramuscular (I.M.)
Administration of medication by needle injection into a muscle in the body.
Intravenous (I. V.)
Administration of medication into a vein.
A sequence of DNA that is spliced out before a protein is made.
In utero
In the uterus.
Invasive cancer
Cancer that has spread beyond its site of origin and is growing into the surrounding tissues. See also Carcinoma.
Inverted nipple
A breast nipple that projects inward. Although usually a congenital condition, when it occurs where it has not previously existed, it may be a sign of breast cancer.
A person performing research, also known as a researcher.
In vivo
In the living organism, a process or reaction that occurs in an organism.
In vitro
In glass, a process or reaction carried out in a culture dish or test tube.
Ion channel
An area in cell membranes through which ions move into or out of cells.
An atom or group of atoms which have lost or gained one or more orbital electrons and have therefore become capable of conducing electricity.
Iridium wire
A radioactive wire often used to deliver a boost to the operative site in breast-conserving techniques.


No terms.


Karnofsky Performance Scale
A system for assessing the functional status of the patient in relation to their disease. One hundred is normal, no complaints, no evidence of disease and zero is dead.


Lobular carcinoma in situ.
See White blood cells.
Life expectancy
The average time a group of people will live. The life expectancy of a birth cohort is the length of time the average person born at that time will live; half the people will live less than that time and half will live longer than that time. The life expectancy of a birth cohort, all the people born in the year you were born, is affected by the infant mortality rate.
A molecule that binds to s specific site on a protein or other molecule.
Linear accelerator
A machine that produces high-energy x-ray beams to destroy cancer cells.
In genetics, the association by inheritance of two or more non-allelic genes due to their being located more or less closely on the same chromosome.
Linkage analysis
A gene-hunting technique that traces patterns of heredity in large, high-risk families in an attempt to locate a disease-causing gene mutation by identifying traits that are co-inherited along with it.
Linked Data files or sets
Combining or linking information from distinct computerized data sets or files, each with unique information. The linkage mechanism is often accomplished by patient identification numbers.
Liver scan
A way of visualizing the liver by injecting into the blood a trace dose of a radioactive substance that makes it possible to visualize the organ via the x-ray.
LNCaP cells
A group of identical human prostate cells that grows in culture and is androgen-responsive.
When used in reference to breast tissue, the part of the breast that is furthest from the nipple, the lobes.
Lobular carcinoma
An invasive (infiltrating) breast cancer, relatively uncommon, accounting for only 10 percent of breast tumors. It is often an area of ill-defined thickening in the breast, in contrast to the dominant lump characteristic of ductal carcinoma. It is typically composed of small cells in a linear arrangement, with a tendency to grow around ducts and lobules.
Lobular carcinoma in situ
An uncommon noninvasive neoplasm characterize by a low proliferative rate and multicentricity. (LCIS)
Localized cancer
A cancer still confined to its site of origin.
Logistic regression method
A statistical method that learns the relationship between a qualitative dependent variable (that is, one that can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. For example, given the patient’s tumor size, what is her chance of dying of the cancer. A common application in epidemiology is estimating an individual's risk (probability of a disease) as a function of a given risk factor.
Longitudinal study
See Cohort study.
Any kind of abnormal mass in the body.
A surgical procedure pertaining to breast cancer during which only the cancerous tumor and an area of surrounding tissue are removed.
A clear fluid circulating throughout the body in the lymphatic system that contains white blood cells and antibodies. It is a component of the body’s immune system.
Lymphatic vessels
Vessels that are like blood vessels except that they remove excess extracellular fluid by filtering it through the lymph nodes. They eventually empty the fluid into the blood.
A swelling of the arm caused by excess lymphatic fluid that collects after the axillary lymph nodes have been removed by surgery or destroyed by radiation treatments. It can be both painful and disfiguring.
Lymph glands
Rounded body tissues in the lymphatic system that vary from the size from a pinhead to an olive and may appear alone or in groups. The principal nodes are located in the neck, underarm, and groin. These glands contain lymphocytes and monocytes (white blood cells that fight foreign substances such as bacteria) and serve as filters to prevent bacteria from entering the bloodstream. The major nodes that serve the breast are located in the armpit. Some are located above and below the collarbone and some in between the ribs near the breastbone. Three levels of lymph nodes can be found in the underarm area and another around the breastbone. The number of nodes varies from person to person. Lymph nodes are usually biopsied during surgery to determine if the cancer has metastasized.
Lymph nodes
See Lymph glands.
Any of the mononuclear, nonphagocytic leukocytes (white blood cells) found in the blood, lymph, and lymphoid tissues that are the body's immunologically competent cells and their precursors. They are divided into two classes, B and T lymphocytes, responsible for humoral and cellular immunity, respectively. Most are small lymphocytes, 7 to 10 micrometers in diameter, with a round or slightly indented heterochromatic nucleus that almost fills the cell and a thin rim of basophilic cytoplasm that contains few granules. When activated by contact with antigen, small lymphocytes begin macromolecular synthesis, the cytoplasm enlarges until the cells are 10 to 30 micrometers in diameter, and the nucleus becomes less completely heterochromatic; they are then referred to as large lymphocytes or lymphoblasts. These cells then proliferate and differentiate into B and T memory cells and into the various effector cell types-B cells into plasma cells and T memory cells and into the various effector cell types and T cells into helper, cytotoxic, and suppressor cells.
Lymphocytes, tumor
Lymphocytes that show specificity for autologous tumor cells.
Dissolution or destruction of cells; loosening or unbinding. The suffix -lytic appears at the end of many words to describe a process that destroys cells.


Messenger RNA.
See Magnetic Resonance Imaging.
A cyst that is large enough to be felt with the fingers.
A white blood cell that acts as a phagocyte, i.e.., a cell-eating organism.
Magnetic Resonance Imaging
A form of imaging that uses magnets instead of radiation and provides a more clearly defined picture of fatty tissue than do traditional x-rays.
Magnification view
Special enlarged views to magnify an area so that a suspicious finding can be examined in greater detail, primarily used in mammography.
Major Histocompatibility Complex
A group of proteins that helps T cells recognize foreign antigens. It can be MHC I or II.
Another name for cancer.
Malignant neoplasm
Another name for cancer.
Malignant tumor
Another name for cancer.
Mammary duct ectasia
A noncancerous breast disease most often occurring during menopause. The ducts in or beneath the nipple become clogged with cellular and fatty debris. The duct may have a gray to greenish discharge and a lump that can be felt, and it can become inflamed and painful.
Mammary glands
The breast glands that produce and carry milk by way of the mammary ducts to the nipples during pregnancy and breast feeding (lactation).
An x-ray of the breast including the mammary glands.
A stereotactic biopsy performed during a mammogram while the breast is compressed and the lesion can be viewed by a physician. Using a large core needle, a sample of the lesion is removed and sent to the laboratory to determine if it is benign or malignant.
The area of tissue that surrounds a tumor and is removed during surgery. To have clean margins means that all the tumor was removed.
Masked study
See Blinded study.
Pain occurring in the breast.
The surgical removal of the breast.
Mastectomy, modified radical
This is the extended radical mastectomy but without removal of the pectoral muscles.
Mastectomy, partial
Excision of part of the breast; in practice, synonymous with complete local excision.
Mastectomy, prophylactic
The surgical removal of the breast prior to the development of cancer. Sometimes recommended for patients at a very high risk of developing the disease.
Mastectomy, radical
The surgical removal of the entire breast including the nipple, areole, and overlying skin, the pectoral muscles, and the axillary and internal mammary nodes.
Mastectomy, segmental
The surgical removal of only a portion of the breast. See lumpectomy.
Mastectomy, simple
The surgical removal of the entire breast including the nipple, areole, and overlying skin.
Mastectomy, subcutaneous
The surgical removal of the breast tissues but sparing the skin, nipple, and areola.
Inflammation in the breast due to infection. Symptoms include pain, tenderness, swelling, redness, and warmth.
Methods used to select a study group (e.g., cases) and a comparison group (e.g., controls) so that they are comparable on factors such as age, sex, race, or gene gender.
Amenorrhea, the end of menstruation, caused by the ovaries reducing their production of female hormones (estrogen, progesterone). Natural menopause is preceded by intermittent amenorrhea (primenopausal) and usually occurs between the ages of 45 and 55. In both chemically induced and natural menopause the FSH is elevated.
Embryonic tissue in the mesoderm from which the connective tissues of the body, the blood vessels, and the lymph vessels are formed.
Messenger RNA
RNA that carries the genetic code (DNA) from the nucleus of the cell to the cytoplasm.
Quantitative procedures for summarizing, integrating, and combining the findings from a literature review of a subject under study. Meta-analysis uses summary statistics from primary analyses of studies, and is therefore a synthesis of results.
Metastatic cancer
Cancer that is found in an area of the body other than the primary site.
Calcium particles in the breast tissue that are detected as small spots on a mammogram as small spots. They are usually caused by the death of breast cells that may be benign or malignant.
A cyst that is too small to be felt but may be observed by mammography or ultrasound screening.
Extremely small areas of metastatic cancer that cannot be detected by physical examination, blood or imaging tests. Special tests must be performed to detect the small number of cancer cells.
See Non-comedo carcinoma.
An agent that induces mitosis and lymphocyte transformation.
The process of cell division. The number of mitoses indicates the number of tumor cells replicating.
A type or class of therapy, such as chemotherapy, surgery, and radiotherapy.
Modified Radical
The most common type of mastectomy. Breast skin, nipple, areola, Mastectomy and underarm lymph nodes are removed, but the chest muscles are saved.
A cell's ability to adapt to an environment.
An equal part; any part or portion, as a portion of a molecule.
Molecular Biology
The field of science involved in the study of subcellular processes. Subcellular processes include DNA, RNA, proteins and receptors.
Molecular Epidemiology
Epidemiological studies that use techniques from molecular biology. In cancer research, these techniques are used to identify, characterize, and measure molecular changes in carcinogenesis, heritable genetic polymorphism, and cancer family genes.
A group of atoms arranged to interact in a particular way; one molecule of any substance is the smallest physical unit of that particular substance.
A prefix meaning single or one.
Disease rate in a given population.
Diffusible substance that carries information relating to position in the embryo and thus determines the differentiation that cells perceiving this information will undergo.
The processes that are responsible for producing the complex shapes of adults from the simple ball of cells that derives from division of the fertilized egg.
Of, relating to, or concerned with form or structure. In cancer, related to the tissue structures observed by pathologists.
The branch of biology that deals with the structure and form of plants and animals. In cancer, related to the tissue structures observed by pathologists. Classifications of a cancer based on what the cancer looks like under a microacope.
Death rate.
The development of cells from a fertilized ovum that have different chromosomes. Normally, all cells have the same chromosomal makeup.
Producing or containing mucous.
More than one origin or place of growth. These growths mayor may not be related to each other.
Multivariate Analysis
A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.
Of, or related to, common rodents (mice and rats).
An agent, including chemicals and radiation, that can cause a genetic mutation.
Mutation, gene
A change in the number, arrangement, or molecular sequence of a gene.
Mutation, hereditary
A gene change in the body's reproductive cells (egg or sperm). Also called a germline mutation.
A decrease in the ability of the bone marrow cells to produce blood cells, including red blood cells, white blood cells, and platelets. This can be caused by infection, disease, drugs, and radiation to the bone marrow.


The lowest measured value, usually used in the context of evaluating the effect of chemotherapy or radiotherapy on the white blood cell and platelet count.
Natural history
The course and outcome of a disease without treatment.
Naturalistic observation
See Observational study.
The death of an individual cell or groups of cells in living tissue that is sometimes seen in carcinomas.
Needle Biopsy
Removal of a sample of tissue using a wide-core needle with suction.
Negative Growth
Inhibits the growth of a cell or substance.
A roundworm.
Neoadjuvant Therapy
Any adjuvant therapy that is given prior to the primary therapy (e.g., surgery) rather than after the primary therapy.
Any abnormal growth. Neoplasms may be benign or malignant, but the term most often is used to describe a cancer, i.e., malignant neoplasm.
Neoplastic Syndromes,
The occurrence of a pattern of malignancies within a family, but not hereditary necessarily the same neoplasm. Characteristically the tumor tends to occur at an earlier than average age, individuals may have more than - one primary tumor, the tumors may be multicentric, usually more than 25 percent of the individuals in direct descent from the proband are affected, and the cancer predisposition in these families behaves as an autosomal dominant trait with about 60 percent penetrance.
Nerve cells that are capable of stimulation and conduct impulses. Neutropenia (febrile) A condition that exists when the numbers of circulating neutrophil leucocytes are reduced. If the numbers fall to very low levels, there is the risk of supervening infection, and the syndrome is then referred to as febrile neutropenia or neutropenic sepsis.
A chemical substance with a pH of 7.0, a pH lower than 7.0 is acid, and a pH of more than 7.0 is alkaline (also known as a basic substance) in the body.
Newborn Screening
Examining blood samples from a newborn infant to detect disease- related abnormalities or deficiencies in gene products.
Nitrogen mustard
A type of chemotherapy, an alkylating agent, includes mechlorethamine, cyclophosphamide.
A type of chemotherapy, an alkylating agent, includes carmustine, streptozocin.
A receptor that is stimulated by injury or functions as a receptor for pain.
Increased density of breast tissue (most often due to hormonal changes) that causes the breast to feel lumpy in texture. This finding is called normal nodularity, and usually occurs in both breasts.
A small, solid mass.
Non-comedo carcinoma
A low-grade type of in situ carcinoma composed of small cells, morphological patterns includes cribriform, micropapillary, or small cell carcinoma.
Normal distribution
A bell-shaped (symmetric and unimodal) curve of the frequencies of a variable where the x-axis is the range of the variable’s values (the ends of the distribution go to infinity in each direction) and the y-axis is the frequency of each values occurrence. The area under the curve represents the probability 1.00. The mean, median, and mode all have the same value. This shape is also called a Gaussian distribution.
Northern Blot
A method of separating and identifying RNA by gel electrophoresis, transfer to a filter (blotting), and hybridization to radioactively labeled RNA or DNA.
Nuclear Magnetic
See Magnetic Resonance Imaging.
Resonance(NMR) Nucleic Acids
The basic compounds that form the genetic material of the cell and direct protein synthesis. Composed of repeating units of nucleotides, the two major classes of nucleic acids are DNA and RNA.
A subunit of DNA or RNA, consisting of one chemical base plus a phosphate molecule and a sugar molecule.
The cell structure that houses the chromosomes.
Nude Mouse
Hairless, immunodeficient mouse that allows tumor transplantation - from other species without being rejected. This allows for human tumors to be studied in a whole animal system. (See also SCID Mouse)


Observational study
A study that does not involve an intervention. Nature is allowed to take her course and the changes in the characteristic(s) under study are observed by the investigator. The case-control study and cohort study are observational studies.
Occult Metastases
Metastases that are not yet apparent.
Odds Ratio
In epidemiology, a comparison of a risk factor for disease in a sample of disease subjects and nondiseased controls. Odds Ratio for a cohort (# people with disease who were exposed to a risk factor/# people with disease who were not exposed) / (# people without disease who were exposed/# people without disease who were - not exposed) This measure should be used for case control studies that retrospectively look at risks in those with and without disease. Also - known as Exposure'Odds Ratio.
PrefIX meaning few or very little.
A family of interferon-induced enzymes that bind double-stranded Synthetases RNA.
Few changes in form (versus many changes, as in polymorphic).
Short DNAIRNA strand with linear sequence of up to 20 nucleotides bonded together. Above this length, the tenn polynucleotide is used.
Short peptide strand with linear sequence of up to 20 amino acids bonded together. Above this length, the tenn polypeptide is used.
Genes that normally play a role in the growth of cells but, when - overexpressed or mutated, can foster the growth of cancer.
A substance (usually a chemical) or radiation that causes cancer.
Oncologic surgeon
A surgeon that specializes in the surgical removal of cancer.
A physician who specializes in the diagnosis and treatment of cancer.
The area of medicine that deals with the causes of cancer, cancer as a disease process, and cancer therapies.
One-step procedure
A procedure during which a surgical biopsy is performed under general anesthesia, and, if cancer is found, a mastectomy or lumpectomy is performed immediately as part of the same operation.
One-tail test
A statistical test of significance (see p-value) that is based on the assumption that the data will have only one possible direction (i.e., positive/benefit or negative/adverse effect); contrasted with a two-tail test of significance.
The complete developmental history of an individual organism.
The surgical removal of the ovaries, sometimes perfonned as a part of hormonal therapy.
Open biopsy
A surgical procedure perfonned under local or general anesthetic in which a sample of tissue for histological examination is obtained.
X-rays delivered from generators operating at fewer than 500,000 volts and usually in the region of 250,000 to 300,000 volts.
A molecular process that maintains intracellular and extracellular body fluids in balance by the shifting of a solvent or fluid (such as water) from an area of low solute (such as sodium or potassium) concentration to an area of high solute concentration.
Change in bones (usually increased brittleness) that occurs with age, - calcium loss, and honnone depletion.
Ablation Treatment that destroys ovarian function.
Overall Survival
The time from the primary treatment of cancer to the death of the patient.
Urinary The inability to maintain bladder control when the bladder is full or Incontinence near full. A protein with complex functions that include mediating cell cycle - arrest after DNA damage. Li-Fraumeni syndrome (which results in a marked increase in the risk of breast cancer) is associated with inherited mutations of the p53 gene. The majority of p53 mutations - result in an abnormal protein that accumulates in cells and thus is easily identified immunohistochemically. Acquired (somatic) mutations are found in approximately 50 percent of breast cancers. See also Tumor-suppressor genes.


Positron emission tomography.
Paget's Disease
An intraductal carcinoma of the breast extending to the nipple and areola, characterized clinically by eczema-like inflammatory skin changes and histologically by infiltration of the dermis by malignant cells (Paget's cells).
Paired samples
Similar to matching in case-control studies and clinical trials so pairs of subjects may be studied.
Palliative treatment
Therapy that relieves symptoms, such as pain or pressure, but does not alter the course of the disease. Its primary purpose is to improve the quality of life.
A benign tumor derived from epithelial structures such as skin, mucous membranes, or glandular ducts.
The development of multiple papillomas.
Signal-releasing substance, usually a hormone, secreted from a cell in close proximity to a target cell.
Parallel pair
An arrangement of x-ray fields that allows radiation to be given in one direction and in the reverse direction and thus balances absorption with depth.
A measurable characteristic of a population such as average height.
Partial mastectomy
Excision of part of the breast; in practice, synonymous with complete local excision. See also Mastectomy.
Patey's Operation
A modified radical operation for carcinoma of the breast in which the breast and axillary lymph nodes are removed in continuity, as in the Halsted operation, but without removal of the pectoralis major muscle. See also Modified Radical Mastectomy.
The biochemical, structural, and physiologic changes that occur - during progression of disease.
A physician with special training in diagnosing diseases from samples of tissue.
The study of disease through the gross and microscopic examination of body tissues and organs. Any tumor suspected of being cancerous must be diagnosed by pathological examination.
The physical and chemical processes involved in disordered functions in tissues, organs, and systems.
PC-3 cells
Androgen-independent human prostatic cancer cell line.
Muscles Muscles attached to the front of the chest wall and extending to the upper arms. The muscles are located under the breasts and are divided into the pectoralis major and the pectoralis minor muscles.
A table, chart, diagram, or list of an individual's ancestors, used in human genetics, in the analysis of inheritance.
The percentage of individuals with a particular genotype that actually display the phenotype associated with that genotype.
A compound of two or more amino acids, the building blocks of I proteins.
Neuropathy A group of disorders characterized by the loss of sensation due to the I degeneration of the nerves involved in the communication between II the central nervous system (the brain and spinal cord) and the rest of the body.
Peripheral Stem
Cell A type of autologous transplant during which blood is passed through Transplantation a machine that removes the stem cells (immature cells from which all blood cells develop), and returns the rest of the blood to the body. This procedure is called leukapheresis and usually takes 3 or 4 hours to complete. The stem cells are treated with drugs to kill any cancer cells and then frozen until they are transplanted. This procedure may be r done alone or with an autologous bone marrow transplant.
Permanent Section
A technique in which a thin slice of biopsy tissue is mounted on a r slide to be examined in order to establish a diagnosis.
Per Os (P.O.)
To take food or medication by mouth.
Dynamic and kinetic mechanisms of exogenous chemical and drug absorption, biotransformation, distribution, release, transport, uptake, and elimination as a function of dosage, and extent and rate of metabolic processes. It includes the toxic effects of a substance.
The study of the body’s absorption, distribution, excretion of chemical substances including drugs.
Phase I clinical trial
A clinical study that evaluates the safety of diagnostic, therapeutic, or prevention drugs, devices, or techniques in a small number of healthy subjects usually for less than one year and to determine the safe dosage range. In addition, it is used to determine drug pharmacologic and pharmacokinetic properties (toxicity, metabolism, absorption, elimination, and preferred route of administration).
Phase II clinical trial
A clinical study that evaluates the effectiveness and dosage of diagnostic, therapeutic, or prevention drugs, devices, or techniques. These studies are performed on several hundred volunteers, including a limited number of patients with the target disease or disorder, usually for less than two years.
Phase III clinical trial
A comparative clinical study to verify the effectiveness of diagnostic, therapeutic, or preventive drugs, devices, or techniques determined in phase II studies. During these trials, patients are monitored closely by physicians to identify any adverse reactions from long-term use. These studies are performed on groups of patients large enough to identify clinically significant responses and usually last about three years.
Phase IV clinical trial
The prospective collection of information after the diagnostic, therapeutic, or prevention drugs, devices, or techniques have been FDA approved for medical use. These studies are often conducted to obtain additional data about the safety and efficacy of a product.
The way a person looks, his or her physical appearance. It is the combination of interactions between the genes themselves (gene-gene interactions) and between the person’s genotype and environment (gene-environment).
The metabolic process of introducing a phosphate group (a chemical compound) into an protein’s organic molecule.
Physical maps
DNA maps that show the location of identifiable landmarks, either genes or distinctive short sequences of DNA. The lowest-resolution physical map shows the banding pattern on the 24 different chromosomes; the highest-resolution map depicts the complete nucleotide sequence of the chromosomes. See also Contig maps.
The branch of science that studies the normal functions of the living organism and its parts, and the physical and chemical factors and processes involved in these functions.
Pilot study
A small-scale test of the methods and procedures that will be used on a larger scale if the pilot study demonstrates that the methods and procedures work, that the study can be accomplished. It can also be used to collect preliminary data to show that there is something important to study so that a larger study is worth doing.
An inactive medication or therapeutic procedure that may be given to a control group. The intervention group is compared to the placebo group in order to determine if the intervention is better than the placebo. This is not the same as comparing the intervention to nothing since in many situations there is a “placebo effect”. A placebo effect is the effect of just doing something to a patient. If there is already an effective intervention then it is not ethical to have a placebo control group. In this situation, the new intervention must be compared to the existing intervention. One problem with Phase III studies is that there is evidence in the Phase II study that the intervention is effective. How then can it be withheld from patients in the Phase III study?
The fluid portion of the blood.
Plasma cells
See B-Lymphocytes.
A small, independently replicating piece of cytoplasmic DNA that can be transferred from one organism to another. Plasmids can become incorporated into the DNA of the host or remain independent.
A small cell fragment that is formed by the bone marrow, circulates in the blood, and goes to the site of bleeding. It is necessary for blood clotting. Platelet transfusions are used in cancer patients to prevent or control bleeding when the number of platelets have decreased as a result of the disease. The critical number of platelets that can trigger a transfusion can be as low as 5,000 per high power field (under a microscope).
The number of chromosome sets in a cell.
Ploidy, deoxyribonucleic acid
A measure of the DNA content of a cell. Tumor growth is commonly accompanied by the accumulation of genetic abnormalities, including changes in the total amount of DNA per cell. From this come the terms diploid (normal complement of chromosomes), tetraploid," ' aneuploid, or polyploid.
Polymerase Chain
In vitro method for producing large amounts of specific DNA or RNA Reaction (PCR) fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The reaction is efficient, specific, and extremely sensitive. Uses for the reaction - include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Presenting many changes in form.
Polymorphic Variations
Appearing in different forms and developmental stages.
Port, Life Port,
Port-A- A device surgically implanted under the skin, usually in the chest, Cath that enters a large blood vessel and is used to deliver medication, chemotherapy, or blood products, or to allow the easy obtaining of blood samples. A port is usually inserted if a person has veins in the arm that are difficult to use for treatment or if certain types of chemotherapy drugs are to be given.
Positron Emission
A scan using radiation to visualize function of an organ such as the Tomography (PET) brain.
Located at the rear or back.
Post-void Dribbling
The inability to shut off urine flow at the end of emptying the bladder, resulting in a small leakage of urine that may last for several minutes.
Post-void Residual
The amount of urine remaining in the bladder after voiding - Volume (urinating). A high post-void residual volume may be a sign of bladder obstruction.
The statistical ability of a study to demonstrate an association between independent variable{s) and dependent variable{s), if one exists. There were enough patients in the study to detect an effect of a certain size.
Precancerous lesion
Abnormal cellular changes that are potentially capable of becoming cancerous. These early lesions may be amenable to treatment. Also called premalignant lesion.
Precipitating Factors
Factors associated with the definitive onset of a disease, illness, accident, behavioral response, or course of action. Usually one factor is more important or more obviously recognizable than others, if several are involved, and one may often be regarded as "necessary." Examples include exposure to an amount or level of an infectious organism, drug, or noxious agent, etc.
Predictive factor
Compare to Prognostic Factor.
Predictive Gene Tests
Tests to identify gene abnormalities that may make a person susceptible to certain diseases or disorders.
Predictive Value
In screening and diagnostic tests, the probability that a person with a (of Tests) positive test is a true positive (i.e., has the disease) is referred to as the predictive value of a positive test; whereas the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.
Preinvasive cancer
See Carcinoma in situ.
Prenatal Diagnosis
Examining fetal cells taken from the amniotic fluid, the primitive placenta (chorion), or the umbilical cord for biochemical, chromosomal, or gene alterations.
Prevalence (rate)
The number or rate of total cases of a disease or event in a specified - population over a specified time period.
Prevalent disease.
Disease that exists in a population prior to screening. See: Incident disease.
Prevention, primary
Prevention of a disease before any signs, symptoms, dysfunction, or anatomical changes occur. See Screening. Prevention, secondary Prevention of manifestations of a disease while it is at an early stage. Prevention, tertiary Prevention of complications of a disease after it has become manifest. Includes surgery, chemotherapy, etc.
Primary tumor
Tumor located in the original site of its development.
The likelihood that a specific event will occur. Usually expressed as a value from 0 (no probability) to 1 (complete certainty), probability is derived from experimental trials and observations of the frequency of i an event relative to other events. See value.
In human genetics, a family member with a diagnosis of disease who first brings the family to the attention of medical investigators. Also - called the index case.
A specific sequence of single-stranded DNA, typically labeled with a - radioactive atom, that is designed to bind to and thereby single out a particular segment of DNA.
Inflammation of the rectum.
Female hormone that is produced by the ovaries during a specific time in the menstrual cycle and that causes the uterus to prepare for - pregnancy and lactation.
Progesterone Receptor
The intracellular receptor that binds progestins and antiprogestins. It - (PR) is an estrogen-induced protein, so it can be used as a marker of functional estrogen receptor status. High expression of PR is associated with a good prognosis.
Progesterone Receptor
A test that is done on cancerous tissue to determine if a breast cancer Assay (PRA) is progesterone-dependent and can be treated by hormonal therapy.
A forecast as to the probable outcome of an attack of disease; the prospect as to recovery from a disease as indicated by the nature and symptoms of the case.
Prognostic Factors
Patient or tumor characteristics that are associated with, but not necessarily causally related to, better or worse disease outcomes. Compare to predictive factor.
The continuing growth of the cancer that is often used when discussing treatment failure; also known as disease progression. Sometimes a 20% increase in tumor size is used to define disease progression.
Protein expressed during S-phase of the cell cycle, and therefore potentially a marker of cellular proliferation.
Proliferating Cell
Nuclear Hormone that stimulates the development of the breasts and later is Antigen (PCNA) essential for initiating and continuing milk production.
chemical believed to promote carcinogenicity or mutanogenicity; a substance that can increase the activity of a catalyst; the region of a genetic operon where transcription is initiated.
Proofreader Genes
See DNA repair genes.
Prophylactic Surgery
Surgery to remove normal tissue that is in danger of becoming cancerous before cancer has the chance to develop. Surgery to remove the breasts of women at high risk of developing breast cancer is known as prophylactic mastectomy.
Prospective study
A study of a group (where the group is defined by a set of entry and exclusion criteria) of people who are free of disease at the start of the study and who vary in their exposure to a possible risk factor. This cohort is followed over time and the incidence rates for disease among those with the risk factor ("exposed") and those without the risk factor ("unexposed") is determined. This study design implies that the cohort is selected in the present and followed into the future. However, the design can be adapted for use with existing data sets, such as medical records. In those situations, subjects can be classified as to their risk factor status in the past and their development of disease in the future. This is called a historical prospective study or a retrospective cohort study. The prospective study is the strongest study design because it allows inferences about causation and can control more biases and threats to study validity. However, it is a lengthy and relatively costly study design.
male gland located below the bladder and surrounding the urethra.
Prostate Specific Antigen
A protein made by the prostate gland and by prostate cancer cells (PSA) that is used to detect potential progression of prostate cancer.
Inflammation of the prostate.
A breast form that can be worn inside a bra. An artificial form used, in the case of breast cancer, following mastectomy.
Prosthetic Breast
Creation of a breast shape using an artificial prosthesis, usually Reconstruction consisting of a silicone envelope containing normal saline or silicone gel.
An enzyme that hydrolyzes (splits bonds) proteins into their constituent peptides.
A large, complex molecule composed of amino acids. The sequence of the amino acids-and thus the function of the protein-is determined by the sequence of the base pairs in the gene that encodes it. Proteins are essential to the structure, function, and regulation of tho body. Examples are enzymes, antibodies, and some hormones.
Protein Product
The protein molecule assembled under the direction of a gene.
The splitting of proteins to form smaller polypeptides through hydrolysis of the peptide bonds.
Precise and detailed plans for the study of a medical or biomedical problem and/or plans for a regimen of therapy.
A cell substance that is generally a translucent colloid material. An estrogen-induced protein that is used as a marker of functioning estrogen receptor status. High expression of pS2 is associated with a good prognosis. value A measure of probability that ranges from 0 to 1 and indicates the degree of belief in a hypothesis. Typically, in health and medical research, the p value is set to <0.05 (or


Excision of an entire quadrant of the breast. The term is often incorrectly used interchangeably with segmentectomy or complete local excision.
Quality of Life
The individual's overall appraisal of his or her situation and subjective sense of well-being. Quality of life encompasses symptoms of disease and side effects of treatment, functional capacity, social interactions and relationships, and occupational functioning. Key psychological aspects include distress, satisfaction with treatment, existential issues, and the impact of illness and treatment on sexuality and body image.
Quiescent Cell
A cell at rest; not replicating or actively secreting.


An old unit of radiation dose now superseded by the gray (1 gray = 100 rads).
See Red blood cells.
See Ribonuclease.
See Ribonucleic acid.
Radiation treats cancer by direct destruction of the tumor cells. It is also used to image the tumor, for example, mammography and CT scans. In the early days of radiation it was thought that radiation was going to cure all cancer, but as researchers began dying of cancer from exposure to radiation, it became clear that radiation can also cause cancer. The atomic bombs dropped on Japan during World War II caused many cases of cancer.
The area of medicine that deals with imaging cancer.
Radiation oncologist
A physician who uses radiation, either by external beam or by implants, to treat cancer.
Radiation therapy
The use of high-energy x-rays or other radiation to kill cancer cells. Radiotherapy and shrink tumors. Radiation may come from a machine outside the body (external radiation therapy) or from putting materials that produce radiation (radioisotopes) in the area where the cancer cells are found (internal radiation therapy).
Radical Mastectomy
See Mastectomy, radical.
An unstable atom that decays to a stable state by emitting radiation - and that is used to kill cancer cells by damaging their DNA. Some also are used to visualize particular organs.
A physician who specializes in diagnosis of diseases through the use - of x-rays.
Randomized Clinical Trial
See Clinical trial, controlled.
Recombinant Clones
Clones containing recombinant DNA molecules.
Recombinant DNA
A combination of DNA molecules formed from two or more different sources.
Formation of new combinations of genes.
Reconstructive surgery
After a mastectomy, the creation or insertion of a breast shape or mound using surgical techniques.
Reconstruction, immediate
Reconstruction of the breast at the time of breast cancer surgery.
Rectus flap
Soft-tissue reconstruction using skin and fat from the abdomen. Reconstruction carried on the rectus abdominis muscle; also known as transverse rectus abdominis myocutaneous (TRAM) flap.
Reappearance of cancer after the tumor became clinically undetectable (cannot be detected on physical examination or by laboratory or radiographic tests) due to successful treatment. If the tumor did not do away one cannot have a recurrence of the disease. Also called relapse.
Resistant to therapy. For example, hormone refractory prostate cancer does not respond to hormone-related therapies.
Regional Involvement
The spread of cancer from its original site to nearby surrounding areas. Regional cancers are confined to one location of the body. Regional involvement in breast cancer could include spread to the lymph nodes or to the chest wall.
Registry or Register
A collection of information at the systems and processes involved in - the establishment, support, management, and operation of such a collection, for example, disease registers. See SEER.
Regression Analysis
A mathematical model that describes the dependent variable as a function of the independent variable{s) or that predicts the dependent variable(s) based on the independent variable(s).
Regions or A DNA base sequence that controls gene expression.
Programs that help patients adjust and return to full, productive lives and that may involve physical therapy, the use of a prosthesis, counseling, and emotional support.
Reappearance of cancer after the tumor became undetectable due to successful treatment. If the tumor did not do away one cannot have a relapse. Also called recurrence.
Relative risk
A comparison of people with the risk factor to those without the risk factor. Expressed as the ratio of incident disease in patients with the risk factor (numerator) to the risk of patients without the risk factor (denominator). See also: Risk ratio.
The degree to which a measure, instrument (including a questionnaire), or procedure can be used in different places or times - or with different populations and yield similar results. If results can be replicated, then the measure, instrument, or procedure is reliable. Reliability is indicated by a statistic.
Partial or complete disappearance of the signs and symptoms of disease in response to treatment, the cancer is clinically undetectable. A complete remission, however, is not necessarily a cure. If there was a complete disappearance of the cancer and it does not return within five years it is called a cure. If there was a complete disappearance of the cancer and it returns at any time it is called a recurrence. Partial remission, or partial response, is defined in various ways depending on the needs of the study but it usually means a 30% - 50% reduction in the size of the tumor for one to six months after treatment.
Renal cell cancer
A type of kidney cancer.
Reproductive cells
Egg and sperm cells. Each reproductive cell splits its 23 pairs of chromosomes, they divide so the egg and sperm carry a set of 23 single chromosomes.
Research Design
See Study design.
A person performing research, also known as an investigator.
Surgical removal of a portion of an organ.
Does not respond to therapy. See Refractory.
See Remission.
Restriction enzymes
Enzymes that can cut strands of DNA at specific base sequences.
Malignant tumor of the retina.
Back of the eye.
Retinoic acid
Vitamin Al acid.
Process of skin pulling in toward breast tissue, often referred to as dimpling.
Retrospective Study
A study design that "looks backwards" to investigate the causes or risk factors that precede the development of a disease. Also referred - to as a case-control study. Specifically, an epidemiologic study that compares cases (people with a disease) and controls (people who do not have the disease) to determine if they differ in their exposure to a suspected risk factor.
Any of a group of RNA-containing viruses that produce reverse transcriptase (DNA is formed from RNA, not vice versa as in normal transcription) and are incorporated into the genetic material of infected cells. Such viruses are known to cause tumors.
Reverse Transcriptase
An enzyme in retroviruses that can construct DNA molecules using RNA as a template, not vice versa as in normal transcription.
Ribonuclease (RNAse)
An enzyme that cleaves RNA.
Ribonucleic Acid (RNA)
A molecular structure formed in the nucleus of all living cells that plays a role in transferring information from DNA to the protein- forming system of the cell.
The probability of some event occurring during some specified time interval. Specifically, the risk of incident (new) disease over a specified time interval.
Risk Assessment
The qualitative or quantitative estimation of the likelihood of adverse - effects that may result from exposure to specified health hazards or from the absence of beneficial influences. The process by which new chemical substances are evaluated for their potential impact on human health, a process that entails determining the substance's toxicity and the number of people exposed to the substance. Risk, attributable In a general population, the proportion of cases with a disease that - can be ascribed to a specific cause or risk factor. In a special or limited population, all members of which have disease, the arithmetic difference between those who have and those who do not have the risk factor.
Risk Factors
A clearly defined occurrence or characteristic that has been associated - with the increased rate of a subsequently occurring disease.
Risk, population
The percentage of cases with a disease that can be ascribed to a attributable specific risk factor.
Risk ratio
See: Relative risk.
Risk Reduction
Interventions used to reduce an individual's or community's probability of developing a certain cancer or disease.
Risk, relative
The ratio between the incidence of a disease among cases with a risk factor in relation to the incidence among those without that factor.


See Single photon emission computed tomography.
Sample Size
The number of units (persons, animals, patients, specified circumstances, etc.) in a population to be studied. The sample size should be large enough to have a high likelihood of detecting a true difference between two groups (power).
Sampling Studies
Studies in which a number of subjects are selected based on a statistical plan or algorithm from all subjects in a defined population. Conclusions based on sample results may be attributed only to the - population sampled.
A tumor made up of a substance like the embryonic connective tissue;tissue composed of closely packed cells embedded in a fibrillar or - homogeneous substance. Sarcomas are often highly malignant.
Scatter Factor
A motility factor that causes colonies of cells in culture to separate - into single cells that move apart or scatter.
SCM Mouse Severe
Combined Immunodeficiency (SCID). Mouse which is immunodeficient (much like a nude mouse) in which tumors from other species can .be transplanted and studied in a whole animal system without being rejected.
In nuclear medicine, the flash of light produced when an x- or gamma ray is absorbed by a radiation detector.
A connective tissue disorder that primarily affects the skin, esophagus, and heart.
Testing for evidence of a particular disease, such as cancer, in persons - with no symptoms of disease. Also called primary prevention.
Secondary Reconstruction
Reconstruction of the breast carried out some time after the original - mastectomy.
Secondary Site
A second site in which cancer is found. For example, cancer in the - lymph nodes near the breast is a secondary site.
Secondary Tumor
A tumor that develops as a result of metastasis or spreads beyond the original cancer site. - SEER Program A cancer registry mandated under the National Cancer Act of 1971 to operate and maintain a population-based cancer reporting system, reporting periodically estimates of cancer incidence and mortality in the United States. The Surveillance, Epidemiology, and End Results (SEER) Program is a continuing project of the National Cancer - Institute of the National Institutes of Health. Among its goals, in addition to assembling and reporting cancer statistics, are the monitoring of annual cancer incident trends and the promoting of studies designed to identify factors amenable to cancer control - interventions. See Registry.
The excision of an entire (radial) segment of the breast.
A measure for assessing the results of diagnostic and screening tests. Sensitivity represents the proportion of diseased persons in a - screened population who are identified as being diseased by the test. It is a measure of the probability of correctly diagnosing a condition.
Sentinel node biopsy
The breast sentinel node is the first lymph node in the axilla that receives lymphatic fluid from the breast cancer, i.e., drains the area of the breast in which the cancer occurred. If the cancer has spread to the axillary lymph nodes via the lymphatic system, then the sentinel node will be the first lymph node to have cancer cells. Before surgery both a radioactive tracer and a dye are injected into the region of the tumor. After sufficient time has elapsed so that the radioactive tracer and the dye can have traveled from the tumor region to the sentinel lymph node, the sentinel node will be identified and removed. During the surgery the node will be examined by a pathologist for evidence that the cancer cells have spread to the axillary lymph nodes. If the sentinel node is found to contain cancer cells the surgeon may decide to remove additional lymph nodes. A side effect of the removal of axillary lymph nodes in lymphedema. Women with enlarged lymph nodes prior to the surgery will undergo a full axillary dissection and the removal of all lymph nodes.
Progressive changes that occur due to disease.
Determination of the order ofnucleotides (base sequences) in a DNA or RNA molecule, or the order of amino acids in a protein.
Producing or containing serum.
Sex Chromosomes
The chromosomes that determine the sex of an organism. Human females have two X chromosomes; males have one X and one Y.
Side effects
An expected effect of a treatment. For example, nausea, vomiting, fatigue, and hair loss may be side effects of chemotherapy.
Signal transduction
The processes by which an extracellular signal (i.e., a hormone) interacts with a receptor at the cell surface, causing a change inside the cell that ultimately causes a change in the cell's functioning.
A 5% or less chance that two things is really the same when we find them to be different. The likelihood that if the test was done one hundred times the same result would occur by chance 5% or less of the times. If the likelihood is 5% or less, less than one out of twenty, it is said to be significant, which means that the observed difference it is unlikely to be due to chance.
Apparatus (resembling a linear accelerator) that allows rehearsal of the treatment position and allows the calculation of the radiation treatment prior to its commencement on a linear accelerator.
Single photon emission computed tomography
A medical imaging method that produces three-dimensional images of physiological functions such as blood flow, oxygen consumption, or glucose metabolism.
Small Cell
Carcinoma See Non-comedo carcinoma in situ.
Soft Tissue
Method of breast reconstruction using the patient's own tissue reconstruction transferred from another area of the body.
A substance dissolved in a solution. A solution consists of a solute and - a solvent.
Pertaining to or characteristic of the body. - Somatic Cells All body cells except the reproductive cells. Somatic Mutations See Acquired mutations.
Southern Blot
A blotting method in which DNA is separated by gel electrophoresis, transferred to a filter, and detected by hybridization to radioactively - labeled RNA or DNA.
A method for assessing the results of a screening test or diagnostic procedure; proportion of people without a disease who are accurately diagnosed as negative by the test or procedure. See Sensitivity.
Specimen X-ray
X-ray of a surgically removed specimen to confirm that a - mammographically detected lesion has been removed; also used to select histological sampling in impalpable lesions and to guide the adequacy of margins.
S Phase
Test performed to determine how many cells within the tumor are at ,;; a particular stage of division.
An evaluation of the extent of a disease, such as cancer; a classification based on stage at diagnosis that helps determine the appropriate treatment and prognosis. In most cancers, it is determined by whether the lymph nodes are involved, whether the - cancer has spread to other parts of the body (through the lymphatic system or bloodstream) and established distant metastases, and the size of the tumor.
Appearing on a mammogram as a star shape because of the irregular growth of cells into surrounding tissue; may be associated with a malignancy or some benign conditions.
Stereotactic needle
Biopsy done while breast is compressed during mammography. A Biopsy series of pictures locate the lesion, and a radiologist enters - information into a computer. The computer calculates the information and positions a needle to remove the finding. A needle is inserted into the lump, and a piece of tissue is removed and sent to the laboratory - for analysis; it may be referred to as a mammotest or core biopsy.
Large family of chemical substances such as hormones, vitamins, and drugs that have chemical structures similar to cholesterol.
Inflammation of the mucous membrane of the gastrointestinal tract creating discomfort and a potential for infection; may be caused by chemotherapy or radiotherapy. Causes nausea and vomiting, can result in loss of appetite.
Stress incontinence
Loss of bladder control during coughing or laughing.
Study design
Generic term to indicate the methods of organizing and implementing a research study. The methods for collecting and utilizing data so that desired information can be obtained with sufficient precision or so that a hypothesis can be tested. Specific types of studies include: prospective, longitudinal, cohort, retrospective study, and case-control.
Smaller than the cell, includes DNA, RNA, proteins, and carbohydrates production, function, and degredation.
A substance that is acted upon by an enzyme.
The clear fluid, overlying material deposited by settling, precipitation, or centrifugation.
Support Group
The existence or availability of people on whom an individual can rely - for the provision of caring, concern, and reinforcement of a sense of personal worth. Other components of support may include provision of practical or material aid, information, guidance, feedback, and - validation of the individual's stressful experiences and coping choices.
Supraclavicular Nodes
The nodes located above the collar bone in the area of the neck.
Surrogate outcome
A biological entity, usually a gene, protein, or compound that is directly related to the disease process. It is usually used to infer whether a therapy was successful before the clinical outcome can be expected to occur. A change in the surrogate outcome, e.g., its reduction or elimination, suggests that the disease has been reduced or eliminated. For example, a lowering of the PSA after treatment suggests that the treatment was successful. Here the PSA is acting as a surrogate outcome. See also Biomarker.
Monitoring the health status of an individual with the disease. For example, checking for recurrence in women with treated breast cancer. In epidemiology, a system of ongoing data collection, analysis, interpretation, and dissemination about one or several diseases or health conditions.
Survival, conditional
The chance of survival over the rest of a specific time interval given that the patient has already survived part of the time interval. For example, if the patient had a 50% chance of living 10 years and the patinet lives five years, the chance of survival for the next five years is greater than 50% because some of the patients who started in the 10 year time interval have already died.
Survival, disease-free
Patients who are alive and without disease. The patients who died with a recurrence, metastasis, or a new second primary are removed and the remaining patients are analyzed in terms of patients who died of the disease compared to the patients who are still alive. It is similar to disease-specific survival except that disease-free removes only those patients who died of other causes and were free of breast cancer. Whereas, disease specific survival removes all patients who die of other causes, even if they had a recurrence of the disease.
Survival, disease-specific
Patients who died of causes other than the disease are removed and the remaining patients are analyzed in terms of patients who died of the disease compared to the patients who are still alive.
Survival, cancer-free
The time from diagnosis to either recurrence, a second cancer, or death from any cause.
Survival, event-free
Used in clinical trials to refer to the length of time after treatment that a person remains free of certain negative events, which can include: severe treatment side effects, cancer recurrence or progression, and death from treatment side effects or from the cancer itself.
Survival, overall
The expected amount of time a person will live before dying of any cause. Overall survival reflects the risk of dying from a specific cancer, plus the risk of dying from any other cause (an accident or another disease, for example). A cancer therapy can have only small effect for an individual patient if that patient is likely to dies of another cause before he or she will die of cancer. Also called total survival or all-cause mortality.
Survival, progression-free
The length of time from detection (or randomization in a clinical trial) to the first evidence of disease progression or death from any cause, whichever occurs first. Progression-free survival includes the amount of time patients have experienced a complete response or a partial response, as well as the amount of time patients have experienced stable disease. In other words, are alive and have not progressed.
Survival, relative
The expected amount of time a person with a particular disease will live, compared with people the same age who do not have that disease. Relative survival provides an estimate of how much a particular disease is expected to shorten a person’s life.
Survival, total
See Overall survival.
Treatment that reaches and affects cells allover the body.


A specific oncoprotein expressed in prostatic cancer cells.
An antiestrogen drug that may be given to women with estrogen- receptive tumors to block estrogen from entering the breast tissues; may produce menopause-like symptoms, including hot flashes and vaginal dryness. Tamoxifen is currently used with high-risk women in clinical trials to prevent breast cancer and with women who have had breast cancer to prevent recurrence.
Fields (radiotherapy target areas) that are planned in such a way that the irradiation of a sector of the chest wall following mastectomy or of the chest wall and breast following breast-conserving surgery minimizes irradiation of the underlying lung.
Taq Polymerase
An enzyme that joins DNA base pairs together and is normally used in the polymerase chain reaction (PCR).
Targeted therapy
A treatment that is given to in a subset of patients with that cancer based on the result of a prognostic factor test. Usually associated with a molecular biologic test.
T Cells
White blood cells that have several functionally distinct subsets, including helper T cells, cytotoxic T cells, and suppressor T cells.
Small, dilated blood vessels that appear in heavily irradiated mucosal - or epithelial surfaces; can also result from other causes.
Radiation therapy delivered from a distance by either Cobalt 60 - apparatus or a linear accelerator.
An enzyme that will elongate the telomere of a chromosome but not - other parts or genes.
The end portion of a chromosome. This part does not contain any - genes that code for proteins.
A decrease in the number of platelets in the blood, resulting in the increased potential for bleeding and decreased ability for clotting.
An organized collection of cells. There are four basic types of tissues in the body: Epithelial, connective, muscle, and nerve. Tissue can also be blood or blood components.
Tissue Expansion
Creation of a breast shape that uses an inflatable silicone envelope placed beneath the skin and muscle and that is gradually expanded over several weeks by repeated injections of saline.
T cells; thymus-dependent lymphocytes; the cells primarily : responsible for cell-mediated immunity. T cells originate from ' lymphoid stem cells that migrate from the bone marrow to the --- thymus and differentiate under the influence of thymic hormones. They are characterized by specific surface antigens. T cell antigen receptors are triggered by antigen only when associated with self major histocompatibility complex antigens, for example, by antigens - processed and presented by macrophages, viral antigens on the surface of host cells, and tumor neoantigens. When activated by an antigen, T cells proliferate and differentiate into T memory cells and - the various types of regulatory and effector T cells.
The unwanted side effects of a drug or other treatment.
The process of copying information from DNA into new strands of messenger RNA (mRNA). The mRNA then carries this information to the cytoplasm, where it serves as the blueprint for the manufacture of ., a specific protein.
The introduction of DNA into a recipient cell and its subsequent - integration into the recipient cell's chromosomal DNA.
DNA integrated into the germ line of transgenic organisms. The DNA - is therefore passed on to the organisms' offspring.
The presence of two genes on opposite chromosomes of a pair.
A mouse model for cancer. Adenocarcinoma of Mouse. Prostate (TRAMP).
Transgenic Mouse
A genetically engineered mouse that has had genes from another organism inserted into its genome through recombinant DNA - techniques. The genetic alteration allows study of how the inserted gene (such as an oncogene) behaves in specific tissues or how it affects tumor development.
See Diaphanography.
The process of turning instructions from mRNA, base by base, into - chain of amino acids that then fold into prot~ins. This process takes,place III the cytoplasm, on structures called nbosomes.
Transrectal llitrasound
A method of imaging the prostate by inserting an ultrasound probe, into the rectum.
Transurethral Resection
A surgical procedure during which tissue is cut from the prostate of the Prostate (TURP) using instruments inserted through the urethra (usually reserved for benign prostatic hyperpeasia and not appropriate for cancer).
Transverse Rectus
See Rectus flap reconstruction. Abdominis Myocutaneous Flap (TRAM).
Treatment Failure
The inability of cancer therapy (whether surgery, radiation, or - chemotherapy) to halt the growth or spread of the cancer. Tubular Carcinoma A well-differentiated carcinoma seen at an increasing rate during mammographic screening. The tumor must be 90 percent tubular to merit the term.
A type of chemotherapy, an alkylating agent, includes dacarbazine.
Triple blinded study
See: Blinded study.
An abnormal growth of tissue. It may be noncancerous (benign) or it may be able to invade adjacent tissues (malignant). See cancer, carcinoma, neoplasm.
Tumor Markers,
biological Molecular products metabolized and secreted by neoplastic tissue and - characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented, including hormones, antigens, amino and nucleic acids, - enzymes, polyamines, and specific cell membrane proteins and lipids.
Tumor-suppressor Genes
Genes that normally restrain cell growth but, when missing or - inactivated by mutation, allow cells to grow uncontrolled.
Tumor Type
The overall histological pattern of the tumor.
Two-step Procedure
When surgical biopsy and breast surgery are performed in two separate surgeries.
Two-tail Test
A statistical test of significance (see p-value) that is based on the assumption that the data will have two possible directions (e.g., benefit or adverse effects); contrasted with a one-tail test of significance.
An amino acid present in most proteins.
Tyrosine Kinase
An enzyme that catalyzes the transfer of energy to tyrosine.


Ultrasound Examination
The use of high-frequency sound waves to image areas inside the body.
Ultrasound Guided Biopsy
The use of ultrasound to guide a biopsy needle to obtain a sample of tissue for analysis by a pathologist.
The tube through which the urine passes from the kidney to the bladder.
The tube that connects to the bladder and through which urine is discharged from the body.
Inflammation of the urethra.


Validation study
A study that uses a new population to determine if the results or inferences of a study are generalizable beyond the initial study population and to test for certain types of study biases. For example, if one finds a serum factor that may be related to a disease at a certain serum concentration, one must test that finding in another population to determine if that amount of the factor is related to the disease.
Validity, test
The extent to which a test measures what it is supposed to measure. Alternatively, the extent to which conclusions drawn from a study are correct.
A statistical term that is used to describe any characteristic, quantity, attribute, phenomenon, or event that varies or that can have different values. Tumor size, age, etc. are variables.
Variable, categorical
A variable with multiple, discrete categories. For example, gender, marital status, and blood type.
Variable, continuous
A variable that is not restricted to certain categories. For example, age, height, and temperature. Continuous variables can be converted into categorical variables by cutting them into ranges.
Variable, dependent
A variable that is the outcome of interest. For example, recurrence, death. Also known as the response variable.
Variable, discrete
A variable that has only integer values. For example, number of births, number of teeth, number of cars.
Variable, independent
A variable that is related to the dependent variable and in some way helps us understand the dependent variable. Also known as the explanatory variable.
A statistical term that describes the degree to which the values of a variable vary in relation to the overall value for that variable. For example, how the patient’s ages are related to the average age of all the patients.
Failure to precisely measure or identify a phenomenon accurately results in an error. Sources for this error can include missing an abnormality, faulty technique resulting in incorrect test measurement, or misinterpretation of the data. Two types of variation are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).
Vascular infiltration
Invasion by carcinoma cells of peritumoral lymphatics or veins.
In infectious disease, an organism that transmits a pathogen (for example, a bacteria or virus) from one organism to another. In molecular biology, a sequence of genetic material that can be used to introduce specific genes into the genome of an organism. These vectors may be able to carry potentially therapeutic genes.
Located toward the abdomen.
Able to survive.


White blood cells.
A beam-modifying device that is used to correct for varying thickness in a field of radiation. It is used in radiotherapy for breast cancer because the thickness of the breast will vary from its apex to its base.
Western blot
A blotting method in which proteins are transferred from a gel to a thin, rigid support and detected by binding of labeled antibody.
Welts, slightly reddened, often changing in size and shape, and extending to nearby areas; usually accompanied by intense itching.
White blood cells
The cells that fight infection in the body. They are divided into two groups by their staining reaction. Granular leukocytes include neutrophils, eosinophils and basophils. Nongranular leukocytes include lymphocytes (T-cells, B-cells) and monocytes.
Wild type
The typical form of an organism as ordinarily encountered in nature, in contrast to natural or laboratory mutations.


The symbol for the chi-square test.
X Chromosome
A sex chromosome. Cells in normal females contain two X chromosomes and cells in normal males contain one X and one Y chromosome.
A tissue graft from one species to another. Xenografting is used to test interventions in nonhumans by placing the tissue in an animal and then applying the intervention. Because the host animal is not human but the tissue is, the results do not always apply to humans.
High-energy radiation. It is used in low doses to produce images of the body and in high doses to treat cancer. High dose radiation can also cause cancer.


Y Chromosome
A sex chromosome. Cells in normal males contain one Y and one X chromosome and cells in normal females do not contain a Y chromosome.


The fertilized egg (ovum) that is the result of the penetration of a female’s egg by a male’s sperm.

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