Prophylactic mastectomy is the surgical removal of both breasts to help prevent breast cancer. Prophylactic mastectomy is a controversial procedure among members of the medical community. Based on recent scientific findings that show prophylactic mastectomy to be effective at preventing breast cancer, some physicians think that it is sometimes defensible. According to the American Cancer Society Board of Directors, “only very strong clinical and/or pathological indications warrant doing this type of ‘preventive operation.”

A contralateral mastectomy is a little different because it is removal of the non-diseased breast at the time of cancer surgery for the other breast. A recent study study examined 56,400 women with breast cancer diagnosed between 1979 and 1999, of whom 1.9% underwent a contralateral prophylactic mastectomy.The observed impact of contralateral mastectomy on the occurrence of breast cancer was profound. The risk was reduced by 97%, adjusting for primary and adjuvant therapy, characteristics of the tumor, and family history.Five women (0.5%) in the contralateral prophylactic mastectomy group developed a contralateral breast cancer despite this procedure. From these data, women may be counseled that their risk will be dramatically reduced but not completely eliminated.

This remains an area of disagreement and controversy. A survey of national policies for coverage, including various medicare policies, revealed that 24% had a formal policy on non-coverage for prophylactic mastectomy even with BRCA positivity. 45% had no policy. Some 30% covered for either BRCA or a strong family history.

Boughey et al states: “The majority of women will obtain no oncologic benefit from CPM, and therefore CPM should be discouraged in average-risk women with unilateral breast cancer. “

Judy C. Boughey et al,Contralateral Prophylactic Mastectomy Consensus Statement from the American Society of Breast Surgeons: Additional Considerations and a Framework for Shared Decision Making, Ann Surg Oncol. 2016; 23(10): 3106–3111.

Narendra Nath Basu et al, The Manchester guidelines for contralateral risk-reducing mastectomy World Journal of Surgical Oncology2015 13:237

NCCN, Breast Cancer 2017