Differences in Toxicity and Outcomes in Clinical Trial Participants From Minority Populations

Black men have a higher prevalence of and mortality rate from prostate cancer compared with White men and have been shown to present with more aggressive and later-stage disease. How prostate cancer treatment affects these racial disparities is still unclear. Several studies have shown that Black men who receive treatment have a more pronounced decrease in prostate cancer-specific death; however, there remains a large disparity in all-cause mortality. This disparity may be in part related to a higher risk of death resulting from comorbidities, given the higher rates of cardiovascular disease and diabetes in Black men, both of which are complicated by the use of androgen-deprivation therapy. To further understand these disparities, it is important that we analyze the racial differences in adverse event rates and severity. Increasing the percentage of Black men in clinical trials will improve the understanding of the biologic drivers of racial disparities in prostate cancer. To evaluate the potential differences in adverse event reporting and demonstrate the feasibility of enrolling equal numbers of Black and White men in trials, we performed a prospective, multicenter study of abiraterone plus prednisone with androgen-deprivation therapy in men with metastatic castration-resistant prostate cancer, stratified by race. Racial differences in prostate-specific antigen kinetics and toxicity profile were demonstrated. Higher rates and severity of adverse events related to adrenal hormone suppression, including hypertension, hypokalemia, and hypomagnesemia, were seen in the Black cohort, not previously reported. Increased enrollment of Black men in prostate cancer clinical trials is imperative to further understand the impact of race on clinical outcomes and treatment tolerability.