Association of race with incidence, characteristics, and mortality from incidental prostate cancer: Analysis of two North American contemporary cohorts

Background: Non-Hispanic Black (NHB) men are at higher risk both for incidence and mortality from prostate cancer (PCa) compared to Non-Hispanic White (NHW) men, but these findings arise from biopsy-detected PCa reports. We aimed to compare the incidence, subsequent management and cancer-specific mortality (CSM) of incidental PCa among NHB and NHW men, using two different North American cohorts. Methods: The Surveillance, Epidemiology and End-Result (SEER: 2004-2017) and our institutional Henry Ford Health (HFH: 1995-2022) databases were queried to identify men diagnosed with incidental PCa. Cumulative incidence estimates were used to calculate CSM differences between NHB and NHW men. Competing-risk multivariable regression analysis tested the impact of race on CSM, after accounting for all available covariates. Results: A total of 418 and 6,124 incidental PCa cases were recorded in HFH and SEER database respectively. No pathological differences were observed between NHB and NHW men in both the cohorts, except for prostate-specific antigen (PSA) value at diagnosis, which was higher in NHB men. At 10-years, the CSM rates were 5.5% vs 7.2% in our cohort and 8.6% vs 10.3% in the SEER cohort for NHW and NHB men, respectively (all Gray's test p-value > 0.05). At multivariable, race was not an independent predictor of CSM in our HFH cohort (HR: 1.46, 95% CI: 0.57-3.71, p = 0.6). In the SEER cohort, NHB men were 34% less likely to die from PCa from 1 year to the next (95% CI: 0.49-0.90, p = 0.008), when compared with NHW men. Conclusions: In the comparison of incidental PCa findings between NHB and NHW men, both groups had similar pathological characteristic and survival outcomes. These findings are different from the 'conventional' screening-detected PCa and suggest that racial differences have minimal to no adverse effects on PCa-specific mortality after incidental diagnosis.