Bilateral Prophylactic Nipple-Sparing Mastectomy: Analysis of the Risk-Reducing Effect in BRCA1/2 Mutation Carriers.

BACKGROUND: Mutations in the BRCA1 or BRCA2 genes increase the lifetime risk of developing breast cancer to 68-72% by the age of 80. One of the modalities to manage the risk is a prophylactic mastectomy. Bilateral nipple-sparing mastectomy specifically offers the most favorable esthetic outcomes but the evidence for its oncological safety remains limited. Thus, we aimed to compare the occurrence of breast cancer between nipple-sparing mastectomy and surveillance groups of BRCA1 or BRCA 2 mutations carriers. MATERIALS AND METHODS: BRCA1 or BRCA2-positive patients undergoing bilateral prophylactic nipple-sparing mastectomy at our department were identified. Only those unaffected by breast cancer were eligible. Each patient was pair-matched with a BRCA1 or BRCA2-positive patient of equal age from the surveillance group. Breast cancer incidence in both groups was recorded and the results were compared. RESULTS: None of 105 patients who underwent NSM between 2009 and 2019 at a single institution with a mean follow-up time of 50 months developed breast cancer over this time period. One patient in this group died of an unrelated cause. Nine patients from 105 in the match-paired surveillance group were diagnosed with breast cancer during a mean follow-up time of 58.3 months, however, none of them died. CONCLUSION: To the best of our knowledge, this is the largest single-center study of risk-reducing bilateral NSM in healthy BRCA1 or BRCA2 mutation carriers. Based on our results and those of other series, we conclude that NSM in its current form appears to be at least equally as safe as other types of mastectomy for preventing breast cancer in BRCA1 or BRCA2 mutation carriers. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Uptake and Effectiveness of Risk-Reducing Surgeries in Unaffected Female BRCA1 and BRCA2 Carriers: A Single Institution Experience in the Czech Republic.

Unnafected female carriers of BRCA1 and BRCA2 pathogenic/likely pathogenic variants (P/LPVs) are at higher risk of breast cancer (BC) and ovarian cancer (OC). In the retrospective single-institution study in the Czech Republic, we analyzed the rate, longitudinal trends, and effectiveness of prophylactic risk-reducing mastectomy (RRM) and risk-reducing salpingo-oophorectomy (RRSO) on the incidence of BC and OC in BRCA1/2 carriers diagnosed between years (y) 2000 to 2020. The study included 496 healthy female BRCA1/2 carriers. The median follow-up was 6.0 years. RRM was performed in 156 (31.5%, mean age 39.3 y, range 22-61 y) and RRSO in 234 (47.2%, mean age 43.2 y, range 28-64 y) BRCA1/2 carriers. A statistically significant increase of RRM (from 12% to 29%) and RRSO (from 31% to 42%) was observed when comparing periods 2005-2012 and 2013-2020 (p < 0.001). BC developed in 15.9% of BRCA1/2 carriers without RRM vs. 0.6% of BRCA1/2 carriers after RRM (HR 20.18, 95% CI 2.78- 146.02; p < 0.001). OC was diagnosed in 4.3% vs. 0% of BRCA1/2 carriers without vs. after RRSO (HR not defined due to 0% occurrence in the RRSO group, p < 0.001). Study results demonstrate a significant increase in the rate of prophylactic surgeries in BRCA1/2 healthy carriers after 2013 and the effectiveness of RRM and RRSO on the incidence of BC and OC in these populations.