New Research Underscores Need for More Diversity in Precision Oncology Studies

Across all studies included, observed-to-expected ratios showed that White and Asian patients were overrepresented while Black patients, Hispanic patients, and American Indian/Alaskan Native patients were underrepresented.

New research highlighted a need for diversifying patients enrolled in clinical trials of precision oncology treatments. The study, published in JAMA Network Open, found that certain racial and ethnic minorities are significantly underrepresented in trials.

The study analyzed data from over 90 studies of patients participating in breast, lung, prostate, and colorectal cancer studies, of which non-Hispanic White patients made up 82.3% of participants, Black patients represented 10%, and Asian patients represented 4.1%.

Researchers calculated the expected number of participants of each racial/ethnic group for each study based on the corresponding US-based proportion. Across all the studies, observed-to-expected ratios showed that White and Asian patients were overrepresented (ratio, 1.35 and 1.46, respectively) while Black patients, Hispanic patients, and American Indian/Alaskan Native patients were underrepresented (ratio, 0.49, 0.24, and 0.43, respectively).

“Increased emphasis on equitable recruitment and enrollment for precision oncology studies is essential, as resulting discoveries are used to personalize treatments, and it is unclear whether current precision medicine breakthroughs can be broadly applicable to, or safe for, our diverse cancer population,” explained authors.

Getting a more granular look at representation, the researchers also investigated trial enrollment by cancer type, finding that lung cancer studies had the highest proportion of White (85.6%) and Asian (4.8%) participants while having the lowest proportion of Black (8.3%), Hispanic (1.1%), and American Indian/Alaskan Native (0.2%) patients.

The findings also showed that:

  • Colorectal cancer studies enrolled the highest proportion of Hispanic patients (5.9%)
  • Prostate cancer studies enrolled the highest proportion of Black (11.2%) and American Indian/Alaskan Native (0.8%) patients
  • Prostate cancer studies enrolled the lowest proportion of Asian patients (1%)

Based on their findings, the researchers called for increased enrollment of a more diverse group of patients in precision oncology studies to allow for more meaningful and representative data.

“Current personalized treatments that are broadly generalized to all individuals based on the presence or absence of a biomarker without fully studying the implications of such treatment in racial and ethnic minority populations may not be appropriate,” commented the researchers. “Even if biological differences are discovered that are unique to certain racial or ethnic minority subgroups, these must be further validated and evaluated for safety and efficacy.”

Similar findings have been well-documented in genome-wide association studies. Data showed that European-ancestry groups make up nearly all (96%) of participants compared with just 0.11%, 0%, and 0.5% of African, African American and Afro-Caribbean, and Hispanic and Latin American ancestry groups.

Reference:

Aldrighetti CM, Niemierko A, Van Allen E, Willers H, and Kamran SC. Racial and ethnic disparities among participants in precision oncology clinical studies. JAMA Netw Open. Published online November 8, 2021. doi:10.1001/jamanetworkopen.20