Abstract B022: Diversity of enrollment in prostate cancer clinical trials: Current status and future directions
Authors: Rencsok Emily , Bazzi Latifa , McKay Rana , Huang Franklin , Friedant Adam , Vinson Jake , Zarif Jelani , Simmons Stacey , Villanti Paul , Kantoff Philip , Heath Elisabeth , George Daniel , Mucci Lorelei 
Published: August 2020

Background: Prostate cancer incidence and mortality rates differ substantially by race and ethnicity globally and within the United States. Despite these disparities, many cancer clinical trials have a lack of representation of U.S. minority groups, and race is often overlooked when reporting trial results. The purpose of this study is to assess diversity of participants in prostate cancer clinical trials.

Methods: Available trials were identified through a systematic review of clinical trials using the U.S. National Library of Medicine's Clinical Trials Database and PubMed. Completed global phase III and phase IV clinical trials evaluating treatment, primary prevention, or screening of prostate cancer with published results were included in the analysis. Trials were analyzed for availability of race and ethnicity data and categories represented. Temporal and geographic trends were analyzed.

Results: Of the 61 treatment-based clinical trials analyzed, 39 (63.9%) reported race data. Twenty-one race categories were represented across the trials, with the largest categories being White (83.2% of participants), Black or African American (7.5%), other/not reported (4.4%), and Asian (2.7%). All other race categories represented less than 2% of participants each. Six trials (9.8%) additionally reported ethnicity data: 81.1% of participants with data were not Hispanic or Latino, 7.6% of participants were Hispanic or Latino, and 11.3% of participants did not indicate their ethnicity. Of four prevention-based trials, all had data available on race, but only one additionally reported ethnicity. The majority of participants in prevention trials were White (84.6%), with similar representation across race and ethnicity categories compared to the treatment clinical trials. Only one of the five screening trials had available race data, again showing majority White participants (85.0%). Categories unique to prevention and screening trials include Hispanic (non-African American), Hispanic (African American), non-Hispanic White, and non-Hispanic Black. The Swedish branch of the European Randomized Study for Screening for Prostate Cancer (ERSPC) reported country of origin rather than race data: 15% of participants were non-European. Additionally, diversity of participants has not changed over time, and representation of countries in trials is unequal.

Conclusions: More than one-third of prostate cancer clinical trials do not report race/ethnicity data. Moreover, there is significant variability in the race categories reported in trials, with 26 categories represented across the analyzed trials. Of the trials reporting race data, over 80% of participants were White. Current initiatives, such as the International Registry of Men with Advanced Prostate Cancer (IRONMAN), are aiming to recruit representative populations to decrease racial and ethnic disparities and ensure that men at risk for or diagnosed with prostate cancer are better represented in research and receive the best possible care.

Citation Format: Emily Rencsok, Latifa Bazzi, Rana McKay, Franklin Huang, Adam Friedant, Jake Vinson, Jelani Zarif, Stacey Simmons, Paul Villanti, Philip Kantoff, Elisabeth Heath, Daniel George, Lorelei Mucci. Diversity of enrollment in prostate cancer clinical trials: Current status and future directions [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B022.