Background: Cost-effectiveness analysis is an important aspect of healthcare, including in Japan, where preventive measures for BRCA1/2 mutation carriers are not covered by health insurance.
Methods: We developed Markov models in a simulated cohort of women aged 35-70 years, and compared outcomes of surveillance with risk-reducing mastectomy (RRM) at age 35, risk-reducing salpingo-oophorectomy (RRSO) at age 45, and both (RRM&RRSO). We used breast and ovarian cancer incidences and adverse event rates from the previous studies, adjuvant chemotherapy, and hormonal therapy rates from the Hereditary Breast and Ovarian Cancer Registration 2015 in Japan, mortality rates from the National Cancer Center Hospital, Japan Society of Clinical Oncology, and Ministry of Health, Labour and Welfare, and direct costs from St. Luke's International Hospital and Keio University Hospital. We used previously published preference ratings of women without known high risk to adjust survival for quality of life. The discount rate was 2%.
Results: Compared with surveillance, RRSO and RRM&RRSO were dominant (both cost-saving and more effective), and RRM was cost-effective in BRCA1 mutation carriers, while RRM and RRM&RRSO were dominant and RRSO was cost-effective in BRCA2. Among the four strategies including surveillance, RRM&RRSO and RRM were the most cost-effective in BRCA1 and BRCA2 mutation carriers, respectively.
Conclusions: With quality adjustment, RRM, RRSO, and RRM&RRSO were all cost-effective preventive strategies in BRCA1/2 mutation carriers, with RRM&RRSO being the most cost-effective in BRCA1 and RRM in BRCA2. This result supports the inclusion of insurance coverage for BRCA mutation carriers in Japan.
Keywords: BRCA1/2 mutation carrier; Cost-effectiveness; Prevention strategy; Risk-reducing mastectomy; Risk-reducing salpingo-oophorectomy.