Abstract P6-10-17: Rates of prophylactic surgeries among BRCA 1 or 2 mutation carriers: A single institution experience

Background Women with identified BRCA1/2 mutation have a substantially increased risk of developing several types of cancer, mainly breast and ovarian, during their lifetime. Management options included close surveillance, chemoprevention and prophylactic surgeries. The aim of this study is to assess the rate of prophylactic surgeries among BRCA1/2 carriers counseled and screened at a single institution in the last 2 decades. Methods We retrospectively captured all women with a BRCA1/2 mutation that were identified in our genetic clinic between 2000 and 2015. The incidence of breast and ovarian cancer among all BRCA carriers was reported. The rates of prophylactic surgeries were calculated and analyzed in all identified carriers. Results Six hundred and eighty four women were identified to carry a deleterious BRCA mutation, among them 364 BRCA1 (53%) and 320 BRCA2 (47%). Three hundred and twenty seven (48%) were diagnosed with breast cancer and 80 (12%) had either ovarian or fallopian tumor. Forty percent (N=271) of the women assessed were healthy carriers. Prophylactic bilateral salpingo-oophorectomies (BSO) were performed in 342 women (50%) and prophylactic mastectomies (PM) (bilateral or unilateral) in 190 (28%). Furthermore, 154 women (23%) had both BSO and PM. Of note, 79 women (12%) were less than 35 years old and 122 were less than 40 years old (18%), the majority of those were waiting to have BSO later on. If we remove the young women from the analysis, 57 and 61% of the women would have had BSO (less than 35 and 40 years excluded respectively). If we only analyze the women who had a recent follow up in our clinic (2014-2015), 422 women would be eligible. Among those, 58 and 84 were less than 35 and 40 years old (y) respectively. For this cohort, the rates of BSO would be 61% (257/422)(whole cohort), 71% (excluding women less than 35y) and 76% (excluding women less than 40y). Conclusion A promising rate of BSO was reported in our cohort of BRCA carriers as compared to the literature. This rate was even higher (from 50 to over 70%) when we only analyzed patients with recent follow up in clinic and when we excluded young women waiting to have BSO. More efforts are needed to determine why the rates of PM are lower, for example limited breast reconstruction resources, in order to reduce the incidence of subsequent invasive breast cancer in this high-risk population. Citation Format: Raphael J, Hewitt P, Graham T, Ott K, Mancuso T, Lorentz J, Emmerson M, Eisen A. Rates of prophylactic surgeries among BRCA 1 or 2 mutation carriers: A single institution experience. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-10-17.