Introduction: The Kaiser Permanent Prostate Cancer (KPPC), Prostate Cancer Prevention Trial (PCPT) and Prostate Biopsy Collaborative Group (PBCG) risk calculators (RCs) improve the detection of high-grade, Gleason Grade Group =2 prostate cancer (HGPCa) but result in excessive biopsies in Black men. Genetic West African Ancestry (WA) is associated with increased risk of HGPCa, but its impact on RC accuracy is unknown. We aimed to validate a tailored RC to improve accuracy and assess if WA can augment accuracy. Methods: We recruited men undergoing prostate biopsy from 5 Chicago clinics from 2009-2014. We split the sample into development (75%) and validation (25%) cohorts. A second cohort from the same sites from 2016-2019 provided external validation. Exclusion criteria were non-Black race and PSA >50ng/ml. We created 2 binary logistic regressions to predict HGPCa using clinical variables alone and including WA. Model accuracy was assessed using area under curve (AUC). Results: 393 Black men were included for development/internal validation, and 354 for external validation. Table 1 shows model performance and comparisons to prior RCs. Conclusions: A tailored RC improves HGPCa prediction in Blacks compared to popular RCs. Including genetic ancestry as a risk factor alongside clinical variables may help alleviate PCa disparities faced by Black men. SOURCE OF Funding: None
