Racial Disparities in Access to Prostate Cancer Clinical Trials: A County-Level Analysis.

Background: African American men have a higher burden of prostate cancer compared with other populations. We sought to determine if they experience disparities in access to prostate cancer clinical trials. Methods: We created a database of all US counties by linking prostate cancer clinical trial data with county-level socioeconomic, demographic, and health-care facility data derived from several external data sources. Using this data linkage, we examined 2 potential access barriers. We investigated the relationship between the proportion of African Americans and access to cancer facilities, adjusting for county population size and other characteristics. Additionally, among counties with cancer facilities, we investigated the relationship between the proportion of African Americans and number of available prostate cancer trials per capita per year. We addressed these questions using logistic and negative binomial regression, respectively. Results: Between 2008 and 2015, 613 prostate cancer trial sites were found among 3145 US counties. Counties with a higher proportion of African Americans were less likely to have cancer facilities (adjusted odds ratio = 0.85, 95% confidence interval = 0.78 to 0.92). Among counties with cancer facilities, those with a higher proportion of African Americans had statistically significantly fewer prostate cancer trials per capita per year (rate ratio per 10% increase in African Americans = 0.90, 95% confidence interval = 0.83 to 0.96). Conclusions: Counties with higher proportions of African Americans seem less likely to have access to cancer facilities. Among counties with cancer facilities, those with higher proportions of African Americans appear to have fewer prostate cancer trials available per capita per year. Clinical trials in prostate cancer therapy should ensure adequate availability of enrollment sites in regions with high concentrations of African Americans.