Germline pathogenic variants in Asian American/Pacific Islander women with breast cancer.

[INTRODUCTION] In 2024, the American Cancer Society reported that Asian American/Pacific Islander (AAPI) women have a rising breast cancer incidence that has surpassed other ethnicities. We aimed to identify the prevalence of pathogenic variants (PV) in the AAPI population with breast cancer and the implications for treatment.

[METHODS] We conducted a prospective cohort study of AAPI women diagnosed with breast cancer between 2020 and 2024 who underwent germline testing.

[RESULTS] Of the 797 AAPI women with breast cancer underwent germline testing, 21.6 % were found to have PVs. Patients with PVs had more aggressive luminal B or triple negative breast cancers (45.3 % vs 16.8 %, p = 0.002) and were more likely to choose contralateral risk-reducing mastectomy (30.2 % vs 15.8 %, p < 0.001). AAPI women with breast cancer and PVs often have dense breast tissue but less frequently personal risk factors for breast cancer.

[CONCLUSIONS] As one in five AAPI women with breast cancer can be found to have a germline pathogenic variant, genetic testing is an influential aspect of surgical and oncologic care. Efforts should be made to improve patient access.