Breast Cancer Prediction Method

Predictions are based on your prognostic factors. These are characteristics that are used to calculate your predictions. The factors are: age, estrogen receptor status, progesterone receptor status, number of positive lymph nodes, tumor size and histologic grade. Your prediction will include a prediction graph and table of the likelihood of non-recurrence or survival for the next fifteen years. Non-recurrence is the chance that you will not have a detectable cancer for the first fifteen years after treatment. Survival is the chance that you will not die from your cancer for the first fifteen years after treatment.

Both the non-recurrence and survival graphs show four separate predictions based on the type of treatment you are receiving: no adjuvant therapy, chemotherapy, hormone therapy, and a combination of chemotherapy and hormone therapy. All non-recurrence and survival predictions are based on the patient having received a primary surgical therapy first (lumpectomy and radiation or modified radical mastectomy).

An advanced statistical method called artificial neural network regression(ANN) is used to make your predictions. Your factors are entered into the artificial neural network model. The model uses this information to predict your chance of non-recurrence (no breast cancer detected) and of being alive over the next fifteen years.

About Breast Cancer

The breast is composed of glands that produce milk for nursing, small ducts to carry the milk to the nipple, fat tissue (which is most of the breast) and fibrous tissue for support. The breast has a rich blood supply and has many lymphatic vessels. The lymphatic vessels drain lymph into the local lymph nodes which are mostly found in the armpit.

There are two main types of breast cancer. The most common type is ductal carcinoma (cancer) which arises in the ducts and accounts for almost 80% of all breast cancers. Cancer that arises in the milk producing glands is called lobular carcinoma (cancer). It accounts for 10% of all breast cancers.

Breast cancer is the most common cancer in women, striking one in eight women. Although the cause of breast cancer is unknown, it has been associated with hereditary factors including the BRCA1 and BRCA2 gene, as well as early age of menarche (the time when a female begins to have her periods), and late onset of menopause.

Breast cancer is unusual in women under 40 years of age. The rate of breast cancer increases with age. Breast cancer tends to be slow growing, although this is not always the case. As the cancer grows, it may spread to the local lymph nodes found in the armpit. This is an important prognostic sign and guide to treatment. Regular mammography testing and breast examination allow us to detect cancer when it is small and before it has had a chance to spread to the lymph nodes.

Primary Breast Cancer Therapy

The primary therapy for breast cancer is surgery, either a lumpectomy and radiation or a modified radical mastectomy. Both procedures have been shown to be equally effective when the cancer has been detected early. All non-recurrence and survival predictions are based on you having received one of these types of surgery as your primary therapy.

Breast Cancer Adjuvant Therapy

Adjuvant therapy means a therapy given in addition to the primary therapy. There are two major types of adjuvant therapy in breast cancer, antiestrogen (tamoxifen) therapy and chemotherapy* (CMF, AC, CAF). The three major chemotherapeutic treatment programs have a similar benefit in most clinical studies.

Antiestrogen therapy is usually most beneficial in women who are estrogen-receptor positive. "Receptors" are found on the surface of the cancer cell, and some cancers have a receptor that binds to the female hormone estrogen. By using an antiestrogen medication like tamoxifen, the growth of the cancer cell can be slowed by preventing estrogen from linking up with the cancer cell receptor. Chemotherapy is usually most beneficial in women who have positive lymph nodes at diagnosis.

*Chemotherapy regimens
CMF, cyclophosphamide, methotrexate, 5-fluorouracil.
AC, doxorubicin, cyclophosphamide.
CAF, cyclophosphamide, doxorubicin, 5-fluorouracil.