Racial Disparities in Future Development of Lethal Prostate Cancer Based on Midlife Baseline Prostate-Specific Antigen.

Abstract

Background: Previous studies found that Midlife Baseline PSA (MB PSA) predicts the risk of developing lethal prostate cancer (PCa), although the cohorts were homogenous in terms of racial compositions. We aimed to investigate racial disparities in the predictive value of MB PSA for lethal PCa in a diverse, contemporary, North American population.

Methods: Our cohort included White and Black men aged 40-59 years, who underwent MB PSA through our health system. Cumulative incidence curves depicted lethal PCa stratified by race and MB PSA above/below the median. We utilized time-dependent Receiver Operating Characteristic (ROC) curves and Area Under the ROC Curve (AUC) to compare the performance of MB PSA in predicting lethal PCa based on race. Multivariable regression (MVA) was used to examine the impact of the MB PSA in predicting lethal PCa by race.

Results: We included 112,967 men, of whom 27% were Black. The cumulative incidence estimate with MB PSA values equal to the median at 15 years of follow-up was 0.13 (0.04, 0.32) for White men and 0.55 (0.24, 1.11) for Black men. AUCs comparison showed no statistically significant differences in the predictive role of MB PSA for lethal PCa between White and Black men. At MVA, using White patients with PSA ≤ median as the reference group, the HR of lethal PCa for White men with PSA > median aged 40-44, 45-49, 50-54, and 55-59 was respectively 2.98 (1.59-5.57), 3.01 (1.89-4.81), 5.10 (3.38-7.70), and 3.38 (2.32-4.92). While for Black men was respectively 5.50 (2.94-10.27), 4.19 (2.59-6.78), 9.79 (6.37-15.04), and 7.53 (5.03-11.26) (all p < 0.001).

Conclusion: Our findings indicate that for the same MB PSA and within the same age category, Black men have a greater risk of developing lethal PCa than White men. A separate cut-off should be created for MB PSA, if this is to be used to guide PSA screening in clinical practice.