Study Finds A Lack Of Representation Of Racial And Ethnic Minorities In Biorepositories For Precision Cancer Research

Researchers from Massachusetts General Hospital (MGH), a founding member of Mass General Brigham, have identified a potential issue with biorepositories created to support precision cancer research and their vast stores of genomic data: lack of sufficient representation of cancer distribution among racial and ethnic minorities. MGH is the original and largest teaching hospital of Harvard Medical School. With an annual research budget of over $1 billion, its Mass General Research Institute is the most extensive hospital-based research program in the United States. It includes more than 9,500 researchers working in more than 30 institutes, centers and departments.

In the paper published in NPJ Precision Oncology, the team pointed out that this could lead to invalid studies attempting to compare mutational profiles between ethnic and racial groups for the most common types of cancer, thus limiting the applicability of any biomarker discoveries to all patient populations. This is largely due to the fact that large biorepositories have historically included mostly white patients.

For the study, the researchers evaluated GENIE’s representation of various patient populations, since it is commonly used in clinical research to describe genomic variations among different racial categories of tumors. Nonetheless, the findings from studies employing the tool often conflict. To evaluate GENIE’s representation compared to the broader cancer populations, the team compared it to the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research (CDC-WONDER), which determines the proportion of cancer patients expected from each racial and ethnic group for a given cancer type. The comparison revealed that White patients were either adequately or overly represented with GENIE for all cancer types, apart from lung cancer and melanoma. Similarly, Asian patients had significant over-representation across several tumor types, including breast, lung, and colorectal cancers. However, other groups had little to no representation. Black patients were found to be underrepresented for most cancers, except melanoma and cervical cancer, and Hispanic patients were consistently underrepresented among all cancers. Additionally, Native American and Pacific Islander patients had zero representation for many cancer types.  

“Our work showed that GENIE is not sufficiently powered to detect small yet potentially clinically meaningful differences between white and non-white patients in even the most common cancer types,” described Sophia Kamran, Assistant Professor of Radiation at Harvard Medical School and co-author of this study.

The press release drew attention to the fact that the low registry representation of minorities could be attributed to a variety of causes, such as systemic exclusion, wariness of research initiatives, and mistrust of clinical research agendas. It further suggested that institutional exclusion and bias may also be contributing factors, which could explain the overrepresentation of some groups and the underrepresentation of others. These findings could have implications for the generalizability of biomarker discoveries to all patient populations, as this could perpetuate existing health disparities. The MGH research unit expressed optimism, however, that a greater understanding of the issue will lead to sustainable progress.