Black Men with Prostate Cancer Treated with Radiation in VA Health System See Improved Outcomes

Black race was found to be associated with improved prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) among men with nonmetastatic prostate cancer who received radiation therapy in a large equal-access health care system, according to study findings published in Cancer.

Additionally, the association of Black race with better morality rates persisted after researchers adjusted for multiple socioeconomic and disease characteristics. However, these findings, which are hypothesis-generating, still require further validation in prospective studies.

“There is a need to continue to mitigate modifiable determinants of racial disparity in prostate cancer,” the authors wrote. “Although providing access to health care does not itself guarantee equal health outcomes, it bridges the divide of racial disparities for men with prostate cancer.”

In this study, researchers conducted a pooled analysis of patients from 152 centers included in the Veterans Health Administration (VA). The study cohort consisted of men who had nonmetastatic prostate diagnosed between 2001 and 2015 and received definitive radiation therapy. Of a total of 31,131 patients included in the study, 9584 (30.8%) were Black.

The primary end point was PCSM, and secondary end points included ACM and the time from a prostate-specific antigen level of 4 ng/mL or more to biopsy and radiation therapy.

“The VA is an ideal setting in which to evaluate the impact of race because all veterans have the ability to access care within the VA health system, reducing the potential for unmeasured confounding variables, such as cost and access to care,” the authors noted. “In addition, the VA central electronic medical record contains robust patient-level and longitudinal data.”

Overall, the 10-year cumulative incidence of death from prostate cancer was found to be lower in Black men compared with white men (4.0% vs 4.8%; P = .004). Moreover, Black race was correlated with a decreased risk of PCSM in a competing risk model (subdistribution HR, 0.79; 95% CI, 0.69-0.92; P = .002). Comparably, the 10-year cumulative incidence of death from any cause was also lower in Black men (27.6% vs 31.8%; P < .001).

Further, in multivariable analysis, Black men were also found to have a 10% decreased risk of ACM (HR, 0.90; 95% CI, 0.85-0.95; P < .001).

“In our large cohort, Black men presented at a younger age and had lower PSA levels, Gleason scores, and clinical stage at diagnosis,” added the authors. “This is contrast to prior studies demonstrating that Black men present with more adverse pathologic characteristics.”

“Routine screening for prostate cancer can lead to early detection of the disease, thereby reducing negative outcomes,” the authors continued. “Equal-access health care environments reduce barriers to screening and diagnosis, which may be a possible explanation for our findings.”

Importantly, the current study did not address the incidence of prostate cancer between Black and white men, which may have contributed to the ratio of prostate cancer deaths by race in this cohort. However, additional studies are already underway which seek to capture linked clinical data with blood and tissue specimens to better understand the biologic drivers of disparities.

Reference:

McKay RR, Sarkar RR, Kumar A, et al. Outcomes of Black Men With Prostate Cancer Treated With Radiation Therapy in the Veterans Health Administration. Cancer. doi: 10.1002/cncr.33224