Breast cancer is a cancer that forms in the cells of the breasts. Breast cancer can occur in women and rarely in men. The symptoms of the breast cancer include a lump in the breast, bloody discharge from the nipple, changes in shape and size of the nipple or breast. There are 2 types of breast cancer: Non-invasive cancers stay within the milk ducts or lobules in the breast. They do not grow or invade in normal tissues within or beyond the breast. Non-invasive cancers are called as carcinoma in situ (in the same place) or pre-cancers. Invasive cancers do grow in normal, healthy tissues. Most breast cancers are invasive. Depending upon the type of cancer the treatment is determined, i.e., whether it is invasive or non-invasive cancer. Treatment varies depending upon the stage of cancer. It may consist of chemotherapy, surgery or radiation.