Increasing Diversity in Clinical Trials: Demographic Trends at the National Cancer Institute, 2005-2020

Background: We described participant demographics for National Cancer Institute (NCI) clinical trials at the clinical center (NCI-CC participants) of the National Institutes of Health to identify enrollment disparities.

Methods: We analyzed NCI-CC data from 2005 to 2020, calculated enrollment fractions, compared with the US cancer population represented by the Surveillance, Epidemiology, and End Results cancer incidence data (2018) and the Cancer in North America database (2018), and compared further with clinical trial disparities data from the NCI Community Oncology Research Program and National Clinical Trials Network (2005-2019), and from ClinicalTrials.gov (2003-2016).

Results: NCI-CC (38 531 participants) had higher enrollment fractions for older adults (8.5%), male (5.6%), non-Hispanic (5.1%), and Black or African American (5.3%) participants; lower women proportion across race and ethnicity; and fewer female sex-specific cancer (6.8%) than male sex-specific cancer (11.7%) participants. NCI-CC had lower median age than Surveillance, Epidemiology, and End Results (54.0 vs 65.4); more Black or African American participants (12.0% vs 11.1%); and fewer women (41.7% vs 49.5%), White (76.1% vs 80.5%), Asian or Pacific Islander (4.6% vs 6.0%), American Indian or Alaska Native (0.3% vs 0.5%), and Hispanic participants (7.1% vs 13%). NCI-CC had more Black or African American and Asian or Pacific Islander participants; fewer Hispanic participants than the NCI Community Oncology Research Program and National Clinical Trials Network; more Black or African American and Hispanic participants; fewer Asian or Pacific Islander participants than ClinicalTrials.gov data. Improvement was noted for NCI-CC (older adults, Black or African American, Asian or Pacific Islander, Hispanic participants).

Conclusion: We found lower representation of older adults, women, Asian or Pacific Islander, American Indian or Alaska Native, and Hispanic participants vs the US cancer population and higher representation of Black or African American vs US cancer population and oncology clinical trials. Multifaceted efforts are underway to reduce disparities in cancer clinical trials at the NCI-CC.