ABSTRACT
The breast (or mammary gland) sits on the pectoralis (chest) muscle (atop the rib cage), and extends horizontally from the edge of the sternum (the firm flat bone in the middle of the chest) out to the midaxillary line (the center of the axilla, or underarm). Breast cancer is the most common malignancy in women, with an annual incidence of 18-90 per 100,000 women worldwide. Molecularly, breast cancer demonstrates gains in chromosomes 1q, 8q, 17q, 20q, and 11q and losses in 8p, 13q, 16q, 18q, and 11q, with mutations most frequently centered on BRCA1, BRCA2, p53, HER2-neu, cyclin D1, and cyclin E. Once a breast cancer is diagnosed, further tests are conducted with cancer tissue to determine the growth potential, likelihood to spread through the body, chance of recurrence, and best treatment options. Five types of standard treatment are used for patients with breast cancer, that is, surgery, chemotherapy, radiation therapy, hormone therapy, and targeted therapy.
