Abstract IA016: Opportunistic salpingectomy for ovarian cancer prevention

Abstract In those at high risk for ovarian cancer, particularly people with a BRCA1/2 mutation, bilateral salpingo-oophorectomy is recommended, which reduces the risk of ovarian or fallopian tube cancers by 80%. However, removal of the ovaries is not recommended for the general population, as it is associated with increased total mortality, coronary heart disease, and osteoporosis. Thus, a different preventive strategy is needed for people at average risk, who make up 80% of cases of HGSCs. The recent understanding that HGSC often originates in the fallopian tube, has led to a primary prevention opportunity for the general population, namely, opportunistic salpingectomy (OS). Opportunistic salpingectomy (OS), the removal of fallopian tubes during hysterectomy or instead of tubal ligation without removal of ovaries, is recommended to prevent ovarian cancer, particularly serous ovarian cancer. This recommendation was made in British Columbia, Canada in 2010 and has been followed by similar recommendations in at least nine other countries worldwide, including the United States. Since the 2010 recommendation in British Columbia, we have used population-based data available in our province to study the safety, cost-effectiveness and most recently, the effectiveness of OS for ovarian cancer prevention. The safety data for OS has been reassuring. HIstorical data have suggested decreased risk among those without fallopian tubes; however, we hypothesized that OS confers more protection than salpingectomies done for diseases that directly impact and distort the fallopian tube, as the intent of OS is complete removal of the fimbriated end of the fallopian tube, which may not occur when salpingectomy is done for other indications. Our recent examination of prospective data of OS in British Columbia revealed of the 25, 889 people who had OS (mean age 40. 2 years, median follow-up 3. 2 years) and 32, 080 who had hysterectomy alone or tubal ligation (mean age 38. 2 years, median follow-up 7. 3 years) during our study period (2008-2017), there were no serous ovarian cancers in the OS group and £5 epithelial ovarian cancers. The age-adjusted expected number was 5. 27 (95% CI 1. 78, 19. 29) serous cancers and 8. 68 (95%CI 3. 36, 26. 58) epithelial ovarian cancers. Age-adjusted expected vs observed numbers of breast (22. 1 expected, 23 observed) and colorectal (9. 35 expected, 8 observed) cancers were not statistically significant different. Thus, the statistically significantly fewer serous and epithelial ovarian cancers seem to be a result of the OS and not due to unmeasured confounding that reduced cancer risk in general. Future research includes: 1) ensuring that all those eligible for OS are counselled about it; 2) expanding opportunities for OS to include other pelvic surgeries; and 3) targeting risk-reducing salpingectomy to individuals at higher than average lifetime risk for ovarian cancer despite not having a known genetic mutation that increases risk. Through this combination the incidence of ovarian cancer may be reduced in the future. Citation Format: Gillian E. Hanley. Opportunistic salpingectomy for ovarian cancer prevention abstract. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84 (5 Suppl₂): Abstract nr IA016.