Disparities in clinical drug trial participation in endometrial cancer: a real-world analysis

Racial disparities in clinical trial participation for uterine cancer have been reported.

We sought to examine disparities of endometrial cancer patient participation in clinical drug trials in a contemporary, real-world population in the United States.

We conducted a retrospective cohort study of patients with advanced or recurrent patients with endometrial cancer diagnosed from 2013 to 2021 using a real-world electronic health record-derived database representing approximately 800 academic and community practice sites across the United States. We used multilevel Poisson regression modeling to analyze the association of clinical drug trial participation with patient, sociodemographic, health system, and cancer factors.

Of 4423 patients with endometrial cancer, 2807 (63.5%) identified as white, 649 (14.7%) Black, 78 (1.8%) Asian, and 964 (21.8%) some other race. Overall, 3.8% of patients with endometrial cancer ever participated in a clinical drug trial. High-risk histology and residence in the Southeast were associated with increased clinical trial participation (risk ratio (RR) 2.28, 95% confidence interval (CI) 1.12-4.62 and RR 2.59, 95% CI 1.26-5.3 respectively). By race, trial participants included 123 (72.4%) White, 18 (10.6%) Black, 1 (0.59%) Asian, and 28 (16.4%) some other race. While Black patients had the greatest proportion of high-risk histology, they were 50.0% less likely than white patients to participate in a clinical trial (RR 0.50, 95% CI 0.30-0.83).

Black patients with endometrial cancer were disproportionately underrepresented in clinical drug trials, despite having higher rates of aggressive cancer histologies. Efforts to increase diversity in endometrial cancer clinical trial participants are needed.