UC San Diego

Background

Disparities in prostate cancer-specific mortality (PCSM) between African American and non-Hispanic White (White) patients have been attributed to biological and systemic factors. We evaluated drivers of these disparities in the Surveillance, Epidemiology, and End Results (SEER) national registry and an equal-access system, the Veterans Health Administration (VHA).

Methods

We identified African American and White patients diagnosed with prostate cancer between 2004 and 2015 in SEER (n = 311 691) and the VHA (n = 90 749). We analyzed the association between race and metastatic disease at presentation using multivariable logistic regression adjusting for sociodemographic factors and PCSM using sequential competing-risks regression adjusting for disease and sociodemographic factors.

Results

The median follow-up was 5.3 years in SEER and 4.7 years in the VHA. African American men were more likely than White men to present with metastatic disease in SEER (adjusted odds ratio = 1.23, 95% confidence interval [CI] = 1.17 to 1.30) but not in the VHA (adjusted odds ratio = 1.07, 95% CI = 0.98 to 1.17). African American vs White race was associated with an increased risk of PCSM in SEER (subdistribution hazard ratio [SHR] = 1.32, 95% CI = 1.10 to 1.60) but not in the VHA (SHR = 1.00, 95% CI = 0.93 to 1.08). Adjusting for disease extent, prostate-specific antigen, and Gleason score eliminated the association between race and PCSM in SEER (aSHR = 1.04, 95% CI = 0.93 to 1.16).

Conclusions

Racial disparities in PCSM were present in a nationally representative registry but not in an equal-access health-care system, because of differences in advanced disease at presentation. Strategies to increase health-care access may bridge the racial disparity in outcomes. Longer follow-up is needed to fully assess mortality outcomes.