Underrepresentation in cancer clinical trials
November 2021
Findings from a recent study published in JAMA Network Open highlighted the lack of representation of diverse racial and ethnic groups in breast, colorectal, lung, and prostate precision oncology clinical trials in the US. The study underlines an urgent need to improve the enrollment of more diverse populations such that all individuals may benefit from breakthroughs in cancer research and personalized therapies.
The Study
In the study, the clinicaltrials.gov registry was searched for US-based clinical trials by cancer type (breast, colorectal, lung, and prostate), that incorporated precision medicine objectives including DNA sequencing, tumour analysis, tumour mutational burden, and genetic testing. Eligible studies were then evaluated for their reporting of racial and ethnic demographic data.
US cancer incidence data by race and ethnicity was collected from the National Cancer Institute’s Surveillance, Epidemiology, and End Result (SEER) database.
Findings
197 clinical trials that met precision oncology measures were examined for race and ethnicity analysis. Of the 197 studies, 93 presented the appropriate data while 104 studies did not report any information about race and ethnicity.
Of the 93 studies, 5867 patients were enrolled:
- 4826 (82.3%) were non-Hispanic White
- 587 (10.0%) were Black
- 238 (4.1%) were Asian
- 200 (3.4%) Hispanic participants
- 16 (0.3%) were American Indian/Alaskan Native
In all precision oncology studies, observed participation to expected participation (based on cancer burden) by race and ethnicity was 1.35 and 1.46 for White and Asian participants (overrepresented). Black participants were substantially underrepresented with an observed to expected ratio of 0.49, Hispanic participants with a radio of 0.24, and American Indian/Alaskan Natives with a ratio of 0.43.
Examining by cancer type, White participants were overrepresented across all cancer types. Asian participants were overrepresented in lung, colorectal, and breast studies. Black and Hispanic participants were underrepresented across all cancer types. American Indian/Alaskan Native participants were represented in very small numbers, therefore are not shown by cancer type.
Conclusions
This study underlines the urgent need to increase recruitment of diverse participants in cancer clinical trials to better understand how treatment outcomes vary according to racial and ethnic differences. While the field of oncology is rapidly migrating towards a personalized medicine approach based on the analysis of tumour biomarkers and genetic/genomic variations, there is a far more limited understanding of the variations in underlying cancer biology among different racial and ethnic groups. This impacts the true generalizability of cancer clinical research to the population at large, and asks the important question of whether all individuals are benefitting equally from cancer research breakthroughs.
However, there are many different barriers to increasing enrollment across more diverse patient groups. Individuals from underrepresented groups’ willingness to participate in clinical research comes from the perceived trustworthiness of the researchers, the institutions that conduct that research, and the information provided about the research studies.
A study that examined African American and Hispanic perspectives on precision medicine found that, while both groups believed that precision medicine can improve health outcomes, both were concerned that the existing disparities in health care access and quality would prevent their communities from benefiting from precision medicine[1].
Strategies for increasing more diverse participation in cancer clinical trials include programs dedicated to patient navigation, patient education about genetics and genetic testing, novel trial designs, increasing diversity among the actual scientists, researchers and clinical trial staff could help to increase trust among participants. Furthermore, better reporting of racial and ethnic demographic data must improve such that the monitoring of any improvements to diversity and representation can be properly observed over time and can serve as the basis for future comparative analyses.
Take away message:
Findings from a recent study highlighted the underrepresentation of diverse racial and ethnic groups in precision medicine clinical trials in the US. Targeted strategies to address the lack of diverse participation in cancer clinical trials are much needed, to ensure more generalizable health data and benefit from cancer research breakthroughs for all individuals.
[1]
Yeh VM, Bergner EM, Bruce MA, et al. Can precision medicine actually help people like me? African American and Hispanic perspectives on the benefits and barriers of precision medicine. Ethn Dis. 2020;30(suppl 1):149-158. doi:10.18865/ed.30.S1.149
