Development and Validation of a Prostate Biopsy Risk Calculator in Black Men.

ABSTRACT

PURPOSE: We sought to develop and validate a prostate biopsy risk calculator for Black men and compare it with the Prostate Cancer Prevention Trial version 2.0, Prostate Biopsy Collaborative Group, and Kaiser Permanente Prostate Cancer Risk Calculators for the detection of Gleason Grade Group (GG) ≥ 2 prostate cancer (PCa). MATERIALS AND METHODS: We prospectively recruited 2 cohorts of men undergoing prostate biopsy from 5 facilities in Chicago. The first cohort was split into development (70%) and internal validation (30%) groups. The second was used for external validation. Iterative logistic regression was used to develop 3 models for predicting GG ≥ 2 PCa. Models were compared for discrimination using the C statistics, calibration curves, and net benefit curves. The frequency of unnecessary biopsies and missed PCas was compared at 10% and 30% risk thresholds. RESULTS: The 2 cohorts included 393 and 292 Black men, respectively. Our first model, Mistry-Sun 1, used serum PSA and prior negative biopsy. Mistry-Sun 2 added abnormal digital rectal exam (DRE) and an interaction term with abnormal DRE and PSA to Mistry-Sun 1. Mistry-Sun 3 added prostate volume, abnormal DRE, and age to Mistry-Sun 1. The C statistics were 0.74, 0.74, and 0.78, respectively, and were similar to or higher than established calculators. At the 10% and 30% risk thresholds our models had the fewest unnecessary biopsies and an appropriate proportion of missed GG ≥ 2 PCas. CONCLUSIONS: Tailoring a risk calculator to detect clinically significant PCa in Black men may improve biopsy decision-making and outcomes compared to tools developed in non-Black populations.