Disparities and Trends in the Participation of Minorities, Women, and the Elderly in Breast, Colorectal, Lung, and Prostate Cancer Clinical Trials

Background: This study was done to determine the representation of minorities, women, and the elderly in National Cancer Institute (NCI) clinical trials.

Methods: This is an analysis in the NCI Clinical Data Update System. Patients were evaluated in breast, colorectal, lung, and prostate cancer trials from 2000 to 2019. Representation in a trial was determined by race/ethnicity, sex, and age. Secondarily, the change in trial participation by multivariable analysis by comparing years 2000 through 2004 to 2015 through 2019 was evaluated.

Results: The cohort included 242,720 participants: 197,320 Non-Hispanic White (81.3%), 21,190 Black (8.7%), 11,587 Hispanic (4.8%), and 6880 Asian/Pacific Islander (2.8%). Black and Hispanic patients were underrepresented for colorectal (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.50-0.67; P < .001 and OR, 0.74; 95% CI, 0.64-0.87; P < .001, respectively), lung (OR, 0.83; 95% CI, 0.76-0.91; P < .001 and 0.66; 95% CI, 0.57-0.77; P < .001, respectively), and prostate cancer trials (OR, 0.85; 95% CI, 0.79-0.92; P < .001 and OR, 0.58; 95% CI, 0.51-0.66; P < .001) between 2015 and 2019. The odds of participation in 2015 to 2019 increased among Black patients in breast (OR, 2.19; 95% CI, 2.07-%2.32; P < .001), lung (OR, 1.54; 95% CI, 1.38-1.73; P < .001), and prostate cancer trials (OR, 1.14; 95% CI, 1.04-1.26; P < .001). The odds of participation in a trial among Hispanic patients increased for breast (OR, 3.32; 95% CI, 3.09-3.56; P < .001), colorectal (OR, 2.46; 95% CI, 2.04-2.96; P < .001), lung (OR, 3.88; 95% CI, 3.20-4.69; P < .001), and prostate cancer (OR, 1.70; 95% CI, 1.42-2.04; P = .005).

Conclusions: This study identified that Black and Hispanic patients remain underrepresented in trials, but in recent years, participation has increased. These findings indicate that minority participation has increased over time, but further efforts are needed.