Model Risk Scores May Underestimate Rate of Biochemical Recurrence in African American Men with Localized Prostate Cancer: A Cohort Analysis of Over 3000 Men

Abstract

Introduction: This study aims to determine if there is a difference in the CAPRA and Kattan model-adjusted risk of biochemical recurrence (BCR) and/or adverse pathology between African American (AAM) and Caucasian men (CM) undergoing radical prostatectomy (RP). Methods: We identified men in the Pennsylvania Urologic Regional Collaborative (PURC) who underwent radical prostatectomy (RP). Cox proportional hazards regression models were used to compare the rate of BCR after RP between CM and AAM adjusting for the CAPRA, CAPRA-S, and pre- and post-operative Kattan model score. Logistic regression models were used to compare the rate of adverse pathology after RP between CM and AAM, adjusting for the same models. Results: The 2-year BCR free survival was lower in AAM (72.5%) compared to Caucasian men (CM) (79.0%), with a hazard ratio (HR) of 1.38 (95% CI 1.16-1.63, p<0.001). The rate of BCR was significantly greater in AAM compared to CM after adjustment for pre-op Kattan (HR 1.29; 95% CI 1.08-1.53; p=0.004), and post-op Kattan scores (HR 1.26; 95% CI 1.05-1.49; p<0.001). There was a trend towards higher BCR rates among AAM after adjustment for CAPRA (HR 1.13; 95% CI 0.95-1.35; p=0.17) and CAPRA-S (HR 1.11; 95% 0.93-1.32; p=0.25), which did not reach statistical significance. The overall rate of adverse pathology was similar between AAM (38.4%) and CM (37.8%) (OR 1.02; 95% CI 0.89-1.17; p=0.72) but was significantly greater in AAM compared to CM after adjusting for CAPRA (OR 1.28; 95% CI 1.10-1.50; p=0.001) and Kattan scores (OR 1.23; 95% CI 1.06-1.43; p=0.007). Conclusion: Our analysis from a large multicenter real world cohort provides further evidence that African American men may have a greater-than predicted rate of BCR and adverse pathology after RP than is currently predicted by CAPRA and Kattan models. Accordingly, AAM may benefit from more frequent use of adjuvant therapies.