Diversity of Enrollment in Prostate Cancer Clinical Trials: Current Status and Future Directions

Abstract

Background: Although there are considerable racial and ethnic disparities in prostate cancer incidence and mortality in the United States and globally, clinical trials often do not reflect disease incidence across racial and ethnic subgroups. This study aims to comprehensively review the reporting of race and ethnicity data and the representation of race and ethnicity across prostate cancer treatment-, prevention-, and screening-based clinical trials.

Methods: Seventy-two global phase III and IV prevention, screening, and treatment prostate cancer clinical trials with enrollment start dates between 1987 and 2016 were analyzed in this study, representing a total of 893,378 individual trial participants. Availability and representation of race and ethnicity data by trial funding type, temporal changes in the racial/ethnic diversity of participants, and geographic representation of countries were assessed.

Results: Of the 72 trials analyzed, 59 (81.9%) had available race data, and 11 (15.3%) of these trials additionally reported ethnicity. Of the trials reporting data, participants were overwhelmingly white men (with the highest proportion in U.S. nonpublicly funded trials), comprising over 96% of the study population. The proportion of white participants in prostate cancer clinical trials has remained at over 80% since 1990. Geographically, Africa and the Caribbean were particularly underrepresented with only 3% of countries included.

Conclusions: Trial participants continue to be majority white despite the known racial disparities in prostate cancer clinical outcomes.

Impact: Current and future trials must use novel recruitment strategies to ensure enrollment of underrepresented men. Targeting the inclusion of African and Caribbean medical centers is crucial to achieve equity in representation.

Conflict of interest statement

Conflicts of interest: None

©2020 American Association for Cancer Research.

Figures

Figure 1.. Inclusion/exclusion criteria for phase III and IV prostate cancer clinical trials.

295 trials were initially identified; 72 were included in the analysis.

Figure 2.. Representation of Races/Ethnicities in Prostate Cancer Clinical Trials over Time.

Individual patients categorized into OMB categories; proportion of patients in each category per 5-year range of trial start date.

Figure 3.. Representation of UN Subregions in Prostate Cancer Clinical Trials.

Proportion of countries in each UN subregion included in analyzed trials.