A mastectomy is a surgical procedure to remove some or all of one or both breasts. It is usually performed as a treatment for breast cancer when the disease has spread throughout the breast or into other parts of the body. A mastectomy can be effective at curing a patient’s cancer and preventing it from recurring.

There are several different types of mastectomies. These include:

• Partial mastectomy. Removal of some of the breast tissue surrounding the tumor and the lining of the chest muscles beneath it. In some cases, lymph nodes under the arm may also be removed. Like a lumpectomy, a partial mastectomy is considered a breast-sparing surgery and leaves the nipple and areola intact. The amount of tissue removed varies widely according to the individual patient’s needs. Tests after the procedure will determine whether the patient will need radiation therapy, chemotherapy or hormone therapy. Other terms for partial mastectomy include segmental mastectomy, wide resection, wide excision and quadrantectomy.
  
  
• Simple mastectomy. Removal of all of the breast tissue, including the lobules, ducts, fatty tissue and a strip of skin with the nipple and areola. Tests after the procedure will determine whether the patient will need radiation therapy, chemotherapy or hormone therapy.
  
  
• Modified radical mastectomy. As with a simple mastectomy, this procedure involves removal of the entire breast. However, it also includes removal of some or most lymph nodes from under the arm. This is the most common mastectomy surgery for women who have their breast removed. Lymph nodes are examined after a modified radical mastectomy to see if the cancer has spread and further treatment is necessary. The modified radical mastectomy has largely replaced the radical mastectomy, which involves removal of the pectoral muscles (chest wall) under the breast and all of the lymph nodes in the axillary area and up to the collarbone. This can result in significant disfigurement, and is rarely performed today.

Women usually do not have mastectomies until after they have been diagnosed with cancer. However, in some cases, a healthy woman may decide to have a preventive mastectomy. Although all women are at risk for breast cancer, family history of the disease places some women at increased risk. Preventive mastectomy can reduce the odds of breast cancer by about 90 percent in women in high-risk and moderate-risk groups, according to the National Cancer Institute.

In addition, women who are treated for breast cancer in one breast may elect to have a preventive mastectomy on the other breast. While a preventive mastectomy (also called prophylactic or risk-reducing mastectomy) dramatically reduces the cancer risk, it does not eliminate it. Breast tissue is widely distributed on the chest wall and can sometimes be found in the armpit and in areas stretching from above the collarbone down to the abdomen. Breast cancer can develop in these tissues even when a mastectomy has been performed.

Factors that place women at a higher risk for breast cancer include:

• History of cancer in one breast
  
  
• Family history of breast cancer on either the mother’s or the father’s side. Women who have several relatives diagnosed with breast cancer prior to age 50 are at especially high risk.
  
  
• Genetic testing that identifies mutations associated with cancer. Women with the mutated genes associated with breast cancer (BRCA1 and BRCA2) have an 80 percent chance of getting breast cancer during their lifetime, according to the American Cancer Society. Research has also found variations of ATM, CHEK2 and RAD51 genes increase the risk of developing breast cancer.
  
  
• Early signs of cancer in the breast such as precancerous cells

Choosing to have a mastectomy is a difficult decision and should be made in consultation with a physician. A patient’s cancer care team can provide information and recommendations that can help with the decision. Some women may choose to seek a second opinion about surgery and additional treatments for their cancers.

In many cases, women who have mastectomies will also choose to undergo subsequent breast reconstruction. This is a surgical procedure in which the breast is rebuilt to resemble the shape the patient had before the mastectomy.

Mastectomy is also one possible treatment option for the rare cases of male breast cancer.