Assuming risk reduction in the range of 90%, a theoretical model suggests that for a group of 30-year-old women with BRCA1 or BRCA2 mutations, RRM would result in an average increased life expectancy of 2.9 to 5.3 years. While these data are useful for public policy decisions, they cannot be individualized for clinical care as they include assumptions that cannot be fully tested. Another study of at-risk women showed a 70% time-tradeoff value, indicating that the women were willing to sacrifice 30% of life expectancy in order to avoid RRM. A cost-effectiveness analysis study estimated that risk-reducing surgery (mastectomy and oophorectomy) is cost-effective compared with surveillance with regard to years of life saved, but not for improved quality of life.
A computer-simulated survival analysis using a Monte Carlo model included breast MRI, mammography, RRM, and risk-reducing salpingo-oophrectomy (RRSO) and examined the impact of each of these on BRCA1 and BRCA2 mutation carriers separately. The most effective strategy was found to be RRSO at age 40 years and RRM at age 25 years, in which case survival at age 70 years approached that of the general population. However, delaying mastectomy until age 40 years, or substituting RRM with screening with breast MRI and mammogram, had little impact on survival estimates. For example, replacing RRM with MRI-based screening in women with RRSO at age 40 years led to a 3% to 5% decrement in survival compared to RRM at age 25 years. As with any model, uncertainty remains due to numerous assumptions; however, this provides additional information for women and their providers who are making these difficult decisions.
The Society of Surgical Oncology has endorsed RRM as an option for women with BRCA1/BRCA2 mutations or strong family histories of breast cancer.
Individual psychological factors have an important role in decision-making about RRM by unaffected women. Research is emerging about psychosocial outcomes of RRM. (Refer to the Psychosocial Outcome Studies section of this summary for more information.)
Level of evidence: 3aii
Risk-reducing salpingo-oophorectomy (RRSO)
In the general population, removal of both ovaries has been associated with a reduction in breast cancer risk of up to 75%, depending on parity, weight, and age at time of artificial menopause. (Refer to the PDQ summary on Breast Cancer Prevention for more information.) A Mayo Clinic study of 680 women at various levels of familial risk found that in women younger than 60 years who had bilateral oophorectomy, the likelihood of breast cancers developing was reduced for all risk groups. Ovarian ablation, however, is associated with important side effects such as hot flashes, impaired sleep habits, vaginal dryness, dyspareunia, and increased risk of osteoporosis and heart disease. A variety of strategies may be necessary to counteract the adverse effects of ovarian ablation.