More than 96% of participants in prostate cancer clinical trials are non-Hispanic white men even though non-Hispanic black men represent 22% of prostate cancer diagnoses, researchers reported in Cancer Epidemiology, Biomarkers, and Prevention. Even more critical, enrollment rates of black or African American men have been declining since 1995.

The researchers looked at data from 844,000 participants in 59 global phase III and IV clinical trials analyzing prevention, screening, and treatment for patients with prostate cancer between 1987 and 2016. They found that 83.4%, 84.6%, and 97.5% of the participants were non-Hispanic white men in the treatment, prevention, and screening trials, respectively, whereas black or African American men comprised 6.7%, 8.5%, and 0.5% of the participants in the treatment, prevention, and screening trials, respectively.

Overall, more than 96% of the participants enrolled across all of the trials were non-Hispanic white men. Additionally, over time, the proportion of black or African American men enrolled in prostate cancer clinical trials decreased from 11.3% in 1995 to 2.8% in 2014.

“It’s important to acknowledge the extent of underrepresentation of minority men in prostate cancer clinical trials so that we can find better ways to support their enrollment in future trials,” the researchers said. “Black men have a disproportionate burden of prostate cancer incidence and mortality compared with white men, and the increased enrollment of black men in prostate cancer clinical trials will help us to learn more about these racial disparities, which could ultimately lead to improved treatment options for this patient population.”