Outcomes of Black men with prostate cancer treated with radiation therapy in the Veterans Health Administration

Abstract

Background: Population-based studies demonstrate that Black men in the United States have an increased risk of death from prostate cancer. Determinants of racial disparities are multifactorial, including socioeconomic and biologic factors.

Methods: The authors conducted a pooled analysis of patients derived from 152 centers within the Veterans Health Administration. The cohort included men who had nonmetastatic prostate diagnosed between 2001 and 2015 and received definitive radiation therapy. The primary endpoint was prostate cancer-specific mortality (PCSM). Secondary endpoints included all-cause mortality (ACM) and the time from a prostate-specific antigen level ≥4 ng/mL to biopsy and radiation therapy. A Cox regression model was performed to adjust for differences between clinical parameters.

Results: Among the 31,131 patients included in the cohort, 9584 (30.8%) were Black. The 10-year cumulative incidence of death from prostate cancer was lower in Black men compared with White men (4.0% vs 4.8%; P = .004). In a competing risk model, Black race was associated with a decreased risk of PCSM (subdistribution hazard ratio, 0.79; 95% CI, 0.69-0.92; P = .002). Similarly, the 10-year cumulative incidence of death from any cause was lower in Black men (27.6% vs 31.8%; P < .001). In multivariable analysis, Black men had a 10% decreased risk of ACM (hazard ratio, 0.90; 95% CI, 0.85-0.95; P < .001).

Conclusions: The current results indicate relatively lower PCSM and ACM among Black men who were included in a large Veterans Health Administration cohort and received radiation therapy as primary treatment for nonmetastatic prostate cancer. There is an ongoing need to continue to understand and mitigate the factors associated with disparities in health care outcomes.

Keywords: African American; Veterans Health Administration; equal access; mortality; prostate cancer; race; radiation; survival.