Insurance expansion shortened time to BRCA testing and facilitated preventive strategies: a single-center cohort study in Japan

A single-center cohort study in Japan found that national insurance coverage for BRCA genetic testing was associated with a shorter interval between breast cancer diagnosis and testing among patients with pathogenic BRCA1 or BRCA2 variants. Among 30 patients who underwent surgery for primary breast cancer, the median interval declined from 2,158 days for patients diagnosed before the April 2020 coverage expansion to 54 days for those diagnosed afterward, a statistically significant difference (p < 0.001). The study examined the timing of genetic testing and its relationship to second primary cancers and subsequent preventive surgery.

Researchers retrospectively analyzed patients with pathogenic BRCA1 or BRCA2 variants treated at a single Japanese institution. The primary comparison was the time from initial cancer diagnosis to BRCA genetic testing before and after national insurance coverage expanded in April 2020. Secondary analyses considered when second primary cancers occurred relative to testing and whether patients subsequently underwent risk-reducing mastectomy or risk-reducing salpingo-oophorectomy.

As a retrospective, observational cohort study with only 30 participants at one center, the research identified an association between coverage expansion and shorter testing delays but did not establish that the policy was the sole cause of the change. Ten patients developed second primary cancers. Eight of those 10 cancers occurred before genetic testing, while two occurred afterward.

The timing of these events was examined as a supportive analysis of the consequences associated with delayed identification of hereditary cancer risk. The findings show that, within this selected cohort, most second primary cancers were diagnosed before the patients’ BRCA status was known. Risk-reducing mastectomy was performed in 19 of 25 eligible patients, or 76.0%.

Risk-reducing salpingo-oophorectomy was performed in 13 of 27 eligible patients, or 48.1%. Analysis of the 19 mastectomy specimens identified occult breast lesions in two cases; both were ductal carcinoma in situ, corresponding to 10.5% of the examined specimens. These observations document the preventive strategies used after testing identified pathogenic BRCA variants in this group.

Overall, the cohort supports a marked association between expanded insurance coverage and reduced time to BRCA testing after a breast cancer diagnosis. The analysis also documents second primary cancers occurring before testing and subsequent use of risk-reducing surgery among known mutation carriers. The authors concluded that earlier access to genetic testing, together with multidisciplinary counseling, may help expand opportunities for preventive strategies in hereditary breast and ovarian cancer.

Because the study was retrospective, restricted to one institution and based on 30 patients, its findings provide evidence about testing timing and preventive-care uptake in this cohort rather than a causal estimate of the policy’s effects across Japan.

Subject of Research: Association between expanded insurance coverage, shorter BRCA testing delays and preventive surgery uptake in a Japanese breast cancer cohort

Article Title: Insurance expansion shortened time to BRCA testing and facilitated preventive strategies: a single-center cohort study in Japan

Article References: Kaneko, M., Nohara, A., Munemoto, M., Nishimura, Y., Kawabata, T., Wakita, S., & Yoshino, H. (2026). Insurance expansion shortened time to BRCA testing and facilitated preventive strategies: a single-center cohort study in Japan. BMC Cancer. https://doi.org/10.1186/s12885-026-16878-3

Image Credits: AI Generated

DOI: 10.1186/s12885-026-16878-3

Keywords: BRCA1, BRCA2, genetic testing, insurance coverage, breast cancer, hereditary cancer, risk-reducing mastectomy, salpingo-oophorectomy, second primary cancers, Japan, retrospective cohort, Insurance