Preventive (prophylactic) bilateral mastectomy: Removing both breasts before cancer is diagnosed can greatly reduce the risk of breast cancer (by up to 97%). It does not completely prevent breast cancer because even a very careful surgeon will leave behind at least a few breast cells. The cells can go on to become cancerous. Some of the reasons for considering this type of surgery may include:
- mutated BRCA genes found by genetic testing
- previous cancer in one breast
- strong family history (breast cancer in several close relatives)
- biopsy specimens showing lobular carcinoma in situ (LCIS)
Second opinions are strongly recommended before any woman decides to have this surgery. The American Cancer Society Board of Directors has stated that "only very strong clinical and/or pathologic indications warrant doing this type of preventive operation." Nonetheless, after careful consideration, this might be the right choice for some women.
Prophylactic oophorectomy (ovary removal): Women with a BRCA mutation may reduce their risk of breast cancer by 50% or more by having their ovaries surgically removed before menopause. This is because the surgery removes the main sources of estrogen in the body (the ovaries).
It is important that women with a BRCA mutation recognize they also have a high risk of developing ovarian cancer. Most doctors recommend that these women have their ovaries surgically removed once they finish having children.