Mainstreaming improved adoption of germline testing for Veterans Affairs patients with metastatic prostate cancer without exacerbating disparities.

To improve germline testing adoption for Veterans Affairs patients with metastatic prostate cancer (mPrCA), new delivery models were introduced to complement genetic consultation (traditional model), including mainstreaming where oncologists perform pre/posttest activities and a hybrid model where oncologists perform informed consent and then refer to genetics. We assessed germline testing adoption by delivery model.We conducted a nationwide cohort study of mPrCA patients ascertained from May 3, 2021, to November 2, 2022, with follow-up through May 3, 2023. We assessed associations between patient and facility characteristics and having or completing germline test orders using Cox proportional hazards models.We identified 18,623 mPrCA patients. The average age was 73.9 years (SD, 8.3; range 35-102) with 59.6% non-Hispanic White and 28.9% non-Hispanic Black patients. The cumulative incidence of germline test orders was 13.7% over 2 years. Non-Hispanic Black patients were more likely than non-Hispanic White patients to have germline test orders (hazard ratio [HR], 1.28; 95% CI, 1.15-1.41) but less likely to complete their orders (HR, 0.81; 95% CI 0.72-0.91). Compared with non-Hispanic White patients, non-Hispanic Black patients were more likely to complete orders under the traditional model (HR, 1.40; 95% CI, 111-1.76), less likely under the hybrid model (HR, 0.62; 95% CI, 0.50-0.77) with no difference under the mainstream model.Mainstreaming germline testing for mPrCA patients improved adoption without introducing disparities between non-Hispanic Black and White patients.