Impact of lower co-payments on risk-reducing salpingo-oophorectomy and BRCAtesting in Japan

Background: In April 2020, insurance coverage for risk-reducing salpingo-oophorectomy (RRSO) for breast cancer patients with hereditary breast and ovarian cancer (HBOC) syndrome and BRCAtesting were started in Japan. We investigated the impact of insurance coverage on the number of RRSO and BRCAtests performed. Methods: The subjects were 370 breast cancer patients and 23 of their relatives who received genetic counseling at our institution between April 2014 and December 2021. Finally, 349 patients and 15 relatives were analyzed. We retrospectively compared the number of BRCAtests, RRSO, insurance status, and co-payment of medical expenses before and after insurance coverage based on medical records. Results: In the 6-year pre-coverage period, 226 patients (mean: 37/year) received genetic counseling and 106 (17/year) received BRCAtesting. In the 21-month post-coverage period, 161 patients (92/year) received genetic counseling and 127 (72/year) received BRCAtesting. The rate of testing/counseling significantly increased in the post-coverage period (46.9% vs. 78.8%; p< .001). The number of patients who were diagnosed with HBOC were 24 (4/year) and 18 (10/year) and RRSO was performed for 7 (1/year) and 11 (6/year) patients in the pre- and post-coverage periods, respectively. The rate of RRSO/HBOC was significantly increased in the post-coverage period (29.1% vs. 61.1%; p= 0.039). RRSO patients' co-payment rates decreased from 64% to 25% pre- and post-coverage. Conclusions: Our findings suggest that decreased co-payments were the primary reason for these increases. Insurance coverage is an important factor when promoting preventive medical services such as RRSO.