Racial disparities in germline testing among men with pancreas, breast and metastatic prostate cancers in two health systems.
Authors: Shevach Jeffrey , Lynch Julie Ann , Candelieri-Surette Danielle , Hubbard Rebecca A. , Alba Patrick , Glanz Karen , Parikh Ravi Bharat , Maxwell Kara Noelle 
Published: June 2023

10549

Background: Germline genetic testing is a guideline-based practice for men with pancreas, breast and metastatic prostate cancers. Emerging evidence in female breast and ovarian cancers suggests that Black patients are less likely to receive germline genetic testing, but it is unclear how disparities extend to male cancers and vary by health system. We examined differences by race in germline genetic testing for men with pancreas, breast and metastatic prostate cancers in equal-access and non-equal access systems. Methods: We conducted a retrospective cohort study of men with newly diagnosed pancreas, breast and metastatic prostate cancers between January 1, 2019, and September 30, 2021. We studied two national cohorts: 1) Veterans receiving care in the Veterans Health Administration (VHA), an equal-access health system, and 2) commercially insured beneficiaries. Data consisted of claims and electronic health record data from the VHA Corporate Data Warehouse and claims data from Optum’s De-Identified Clinformatics Data Mart Database (2007-2021). Current Procedural Terminology codes ± laboratory orders and results, and genetic services notes were used to ascertain germline testing prior to the end of the study period. Cox proportional hazards models were used to test the association of non-Hispanic White vs. Black race with the primary outcome of germline genetic testing completion, adjusted for baseline covariates (age, cancer subtype, census region, diagnosis year, Elixhauser comorbidity index and Agent Orange exposure [VHA only]). Results: Our cohort consisted of 7,894 men (5,142 commercially-insured; 2,752 Veterans), including 1,589 Black men (779 [15.1%] commercially-insured; 810 [24.9%] Veterans). Among commercially-insured beneficiaries, one-year germline genetic testing rates were higher in White compared with Black men (18.8% vs. 13.1%; log-rank p < 0.001). Among Veterans, one-year germline genetic testing rates were similar for White and Black Veterans (13.1% vs. 16.9%; log-rank p = 0.335). After adjusting for baseline covariates, Black race was associated with a lower hazard of testing among commercially-insured beneficiaries (adjusted hazard ratio [aHR] 0.72; 95% confidence interval [CI] 0.58 – 0.90; p = 0.004), but not among Veterans (aHR 0.99; 95% CI: 0.79 – 1.25; p = 0.960). Conclusions: This is the first study to examine disparities in germline genetic testing across equal-access and non-equal access healthcare systems, and the largest national study examining germline genetic testing completion in men. While overall rates of testing were similar between Veterans and commercially-insured beneficiaries, racial disparities in testing were observed in non-equal-access settings but not in equal-access settings. Access to care, cost, and other sequelae of structural racism may impact access to guideline-based germline testing.