Abstract B036: Trends in disparities in clinical trial accrual: An analysis of National Cancer Institute (NCI)-sponsored early phase clinical trials over the last 22 years
Authors: Farooq Maria , Sharon Elad , Takebe Naoko , Best Ana F. , Finnigan Shanda 
Published: December 2023

Using the NCI Cancer Therapy Evaluation Program (CTEP)-sponsored early phase oncology clinical trials database, we evaluated trends in disparities in patient enrollment over the last 22 years. Counts and percentages of enrolled patients were calculated directly from the full population of patients enrolled to CTEP-sponsored Phase 1, 2, and 1/2 trials during 2000-22. Trends in enrollment were assessed based on single-year data, four-year periods, and using a three-year rolling average. Analyses of patient residential ZIP code were restricted to patients residing and enrolled at institutions within the United States. Geographical data corresponding to patient ZIP codes was obtained using the zipcodeR package, including geographical region and median household income corresponding to each ZIP, and distance between patient residential and enrolling institution ZIPs. A total of 14,877 patients were enrolled in CTEP-sponsored early phase trials evaluated during 2000-22, with 14,342 residing and enrolled within the US. The proportion of patients aged 40-64 at enrollment decreased from 59.8% in 2000-03 to 47.5% in 2020-22, with corresponding increases in ages 65-74 (24.2% to 32.9%) and 75-84 (5.9% to 12.3%). There were fluctuations in gender, most likely based on the specific agents being studied in clinical trials enrolling at a given time. In 2020-22, 72.9% of the population was non-Hispanic white when compared to 2000-03 when enrollment of non-Hispanic whites was 83.7%. Hispanic/Latino population enrollment increased from 4.2% in years 2000-03 to 6.9% in years 2020-22. Asian/Pacific Islander population increased from 2.5% in 2000-03 to 5.4% in 2020-22. Enrollment of non-Hispanic Black patients increased slightly over the last 20 years (6.3% to 7.1%), as did the proportion with unknown or unspecified race/ethnicity (3.3% to 7.6%). Trial enrollment trends by geographic regions revealed that enrollment in South and West overall increased (29.1% to 40.9%; 7.9% to 18.2%), Northeast representation remained static (23.9% to 20.8%) and Midwest representation decreased (24.4% to 19.4%) from 2000-03 to 2020-22. Most early phase participants in our database were from localities with a moderate median household income ($52,200 - $156,600; 51.9% to 59.4%), with an increase in representation from low-income localities (income &lt; $52,000; 31.1% to 37.7%) over the last 22 years. We observed an overall increase in patients enrolling within a 50-mile radius of their residence over the 22-year period (46.5% to 64.5%) and an overall decrease in patients traveling over 200 miles to enroll in clinical trials (16.1% to 8.3%). We also examined trends in disparities during the COVID-19 pandemic and saw no significant differences in trial enrollment by race/ethnicity and gender when compared to pre-pandemic enrollment. Disparities in patients enrolled in early-phase clinical trials have marginally improved over the span of two decades, and outreach and inclusion efforts for enrollment of underrepresented patients should be continued to sustain these observed trends.

Citation Format: Maria Farooq, Elad Sharon, Naoko Takebe, Ana F. Best, Shanda Finnigan. Trends in disparities in clinical trial accrual: An analysis of National Cancer Institute (NCI)-sponsored early phase clinical trials over the last 22 years [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B036.