Breast cancer is a malignant tumor that starts in the cells of the breast and can spread to other tissues. It occurs almost entirely in women but also in men. There are an estimated 232,340 new cases of invasive breast cancer and 64,640 new cases of non-invasive breast cancer in the United States in 2013. Signs of breast cancer include a new lump or change in size/shape of the breast or discharge from the nipple. Treatment options include surgery, radiation, chemotherapy, hormone therapy and targeted therapy.