Some women, on the advice of their doctors, may choose to have their breasts removed as a precautionary measure if they are at a high risk for breast cancer. A prophylactic mastectomy can lower breast cancer risk by at least 95 percent in women with BRCA1 or BRCA2 gene mutations or with a strong family history of breast cancer, according to the National Cancer Institute. If you have a prophylactic mastectomy, you may want to combine it with breast reconstruction surgery. Some women with cancer in one breast choose to have a prophylactic mastectomy of the other breast to reduce the risk of future breast cancers. But for the average woman with breast cancer, the risk of cancer in the other breast is low enough that this is not medically necessary. A prophylactic mastectomy is not the only risk-reducing option available to women at an increased risk of breast cancer development. For premenopausal women with BRCA mutations, removal of the ovaries reduces the risk of breast cancer as well as the risk of ovarian cancer, which is also higher among women with BRCA mutations. Treatment with drugs such as tamoxifen has been shown to reduce the risk for breast cancer by almost half for some patients. MSK offers a comprehensive long-term screening program for women at an increased breast cancer risk. Read about an MSK patient who chose to have a preventive mastectomy after she learned she had a BRCA mutation.