Abstract
PURPOSE: Genetic testing is recommended but underutilized in advanced prostate cancer. Given known disparities affecting Black patients, we assessed genetic testing completion rates by race. METHODS: Henry Ford Health's electronic medical record was queried for new prostate cancer diagnoses (1/1/2017-6/30/2022). The primary outcome was completion of somatic and/or germline testing in stage IV cases. Secondary outcomes included genetic counseling referrals and attendance. Multivariable logistic regression assessed associations with baseline variables. Kaplan-Meier analysis was used for exploratory survival comparisons. RESULTS: Among 452 stage IV patients (150 Black, 302 White), Black patients had higher somatic (30.7% vs. 18.9%, p = 0.00489) and comparable germline testing rates (16.7% vs. 21.2%, p = 0.255). In M1 cases (N = 297), germline testing was lower among Black patients (14.8% vs. 25.4%, p = 0.0329) despite higher referral rates (32.0% vs 22.2%, p = 0.0241) and similar counseling attendance (45.8% and 43.3%, p = 0.786). No significant racial differences were seen in germline testing for N1 cases (N = 155, 21.4% vs 14.2%, p = 0.274), or somatic testing for M1 (36.1% vs 25.9%, p = 0.0644) or N1 (16.7% vs 7.1%, p = 0.0728) subgroups. M1 patients that completed testing had improved survival (p = 0.0352), while no survival difference by testing in N1 disease or race was observed. CONCLUSIONS: Genetic testing uptake in this advanced prostate cancer cohort was low overall. Notably, Black patients had higher rates of somatic testing, an equitable finding given historically higher prostate cancer-specific mortality. Germline testing was comparable overall but remained lower among Black patients with metastatic disease, indicating that additional decisional and systemic barriers persist beyond access to care and referrals to genetic counseling. Insurance disparities and lower census tract-estimated income represent the largest structural differences between cohorts, with observed equity likely supported by broad coverage of commercial testing. Together, these results indicate that equitable testing utilization is achievable through consistent access frameworks, while residual disparities in germline testing warrant targeted intervention at both the patient and healthcare delivery levels.