Breast cancer is a condition characterized by abnormal cell growth that starts in the breast. The disease mostly affects women, and occurs relatively rarely in men. Some risk factors for breast cancer include having a family history of the disease, abusing alcohol, and having dense breast tissue. Tests and procedures doctors use to help diagnose the cancer may include mammograms, ultrasounds, MRIs, and biopsies. A few examples of possible treatments for breast cancer include surgery, radiotherapy, and chemotherapy.