Implementation of Risk-Reducing Surgery for HBOC Under Public Insurance in Japan: A Single-Center Experience

Abstract Background: In Japan, BRCA1/2 genetic testing and risk-reducing surgeries for hereditary breast and ovarian cancer (HBOC) became covered by public insurance in 2018 and 2020, respectively. These policy changes have improved access to preventive care by lowering financial barriers. This study examined the clinical uptake and timing of risk-reducing salpingo-oophorectomy (RRSO) and mastectomy (RRM) among women with HBOC. Methods: We retrospectively reviewed clinical records of HBOC patients who underwent RRSO and/or RRM under public insurance at a single institution between April 2020 and December 2024. Descriptive statistics and chi-square tests were performed. Results: Among 23 women, 15 (65.2%) underwent RRM, 18 (78.3%) underwent RRSO, and 10 (43.5%) received both. All had a history of breast cancer but had not developed ovarian cancer. The average interval from HBOC diagnosis to surgery was 6.5 months for RRM and 11.3 months for RRSO. BRCA2 carriers had significantly longer delays to RRSO than BRCA1 carriers (p = .02). Three women deferred RRSO due to desire for childbearing. Conclusion: Insurance coverage facilitated preventive surgery uptake, underscoring the need for individualized counseling, particularly for BRCA2 carriers.