3. Mastectomy: Mastectomy is a surgery designed for the removal of all breast tissue, from the breast, nipple, and areola to the sentinel lymph node or nodes. It is usually a breast cancer treatment, but it can also be used to prevent the disease in people with a high probability of developing it. Mastectomy is an umbrella term, however, and there are differences among the procedures that comprise the surgical category. Find out more on how mastectomy can be used as a breast cancer treatment.