Breast cancer is the development of abnormal cells within the breast tissue.
These cells grow and replace normal healthy tissue. Breast cancer is a treatable disease. Early detection is key to surviving breast cancer. Seventy-five percent of women who have small tumors that are diagnosed before the cancer spreads to other parts of the body survive beyond 10 years after the cancer is first diagnosed. At first, the cancer is a small, firm, usually painless lump, not noticeable unless someone is looking for it.