Prophylactic total or simple mastectomy, not subcutaneous mastectomy, for patients at high risk of breast cancer is a difficult issue in that it involves the determination of risk in an individual patient, a separate determination of what level of risk is high enough to justify the extreme choice of prophylactic mastectomy, and assurance from scientific studies in the medical literature that this procedure does result in a reduction of breast cancer occurrence. In addition, the approach among surgeons differs from that of medical oncologists. Even if the risk can be estimated, the decision to proceed with a prophylactic mastectomy will be largely patient driven, dependent on whether the patient feels comfortable living with the estimated risk and how she values the psychosexual function of the breast. Although the definition of “high risk” is somewhat arbitrary, the consensus of opinion is that prophylactic mastectomy may be considered only in patients at high risk of breast cancer with a demonstrated BRCA gene mutation or a life-long risk level in excess of 25-30%.
BRCA1 and BRCA2 may be responsible for only 5% to 10% of all breast cancers and about 20% of breast cancers diagnosed in women under age 45. About 50%-60% of women with inherited BRCA1 or BRCA2 mutations will develop breast cancer by the age of 70. Provisional recommendations by the Cancer Genetics Studies Consortium for follow up of individuals with BRCA1 or BRCA2 mutations involve counseling and early breast cancer screening, including annual mammography and clinical breast examination beginning at age 25 to 35 years, and monthly breast self-examination beginning at age 18 to 21 years. A few recent studies have shown that among women who test positive for a BRCA1 or BRCA2 gene mutation, prophylactic surgery at a young age substantially improves survival.
Even among women with breast cancer in their families, the tests for BRCA1 and BRCA2 may be negative 90% of the time, unless a mutation has been previously identified in the family. A negative BRCA1 and BRCA2 test result would mean that a woman still faces the same risk as the general population of developing sporadic, non-inherited breast cancer. However, in such BRCA negative patients, other significant risk factors come into play. A personal history of invasive breast cancer or lobular carcinoma in situ increases the risk of developing a new breast cancer in any remaining breast tissue in either breast by 0.5% to 1.0% per year.
The degree of reduction of risk of breast cancer with prophylactic mastectomy is not well documented in the literature. All studies were observational studies with some methodological limitations; no randomized trials exist. All studies reporting on incidence of breast cancer and disease-specific mortality reported reductions after Bilateral Prophylactin MMastectomies including those with BRCA1 and 2 mutations. Nine studies assessed psychosocial measures; most reported high levels of satisfaction with the decision to have prophylactic mastectomy (PM) but more variable satisfaction with cosmetic results. Worry over breast cancer was significantly reduced after BPM when compared both to baseline worry levels and to the groups who opted for surveillance rather than BPM.
For Contralateral PM, studies consistently reported reductions in contralateral incidence of breast cancer but were inconsistent about improvements in disease-specific survival. Only one study attempted to control for multiple differences between intervention groups; this study showed no overall survival advantage for CPM at 15 years. Two case series were exclusively focused on adverse events from prophylactic mastectomy with reconstruction; both reported rates of unanticipated re-operations from 30% to 49%.
While published observational studies demonstrated that BPM was effective in reducing both the incidence of, and death from, breast cancer, more rigorous prospective studies (ideally randomized trials) are needed. BPM should be considered only among those at very high risk of disease. There is insufficient evidence that CPM improves survival.
American Society of Surgical Oncology recommends prophylactic mastectomies for patients a HIgh RIsk. This is how it defines High Risk: 1
BRCA mutations or other genetic susceptibility genes
•Strong family history with no demonstrable mutation
•Histologic risk factors
NCCN also recommends prophylactic mastectomies only for high risk women. It its definition it is those who have a known genetic mutation. 2
Lostumbo L, Carbine N, Wallace J, Ezzo J. Prophylactic mastectomy for the prevention of breast cancer. Cochrane Database Syst Rev. 2004;(3).
Sakorafas GH, Tsiotou AG. Prophylactic mastectomy; evolving perspectives. Eur J Cancer. 2000;36(5):567-578.
Solomon JS, Brunicardi CF, Friedman JD. Evaluation and treatment of BRCA-positive patients. Plast Reconstr Surg. 2000;105(2):714-719.
For BRCA positive women see here