Biorepositories created to support precision cancer research through their vast stores of genomic data may lack sufficient representation of cancer distribution among racial and ethnic minorities, according to a new study published by Cheung et al in npj Precision Oncology.
The investigators also reported that this omission may impact the validity of studies directly comparing mutational profiles between ethnic and racial groups for the most common types of cancer, thus limiting generalization of biomarker discoveries to all patient populations.
Background
Large biorepositories—designed to help scientists better understand and treat cancers—have historically included mostly White patients.
“Our findings suggest that these data registries do not reflect the true landscape of patients [with cancer] in the United States and may therefore misrepresent the disease burden in many racial [and] ethnic minority populations,” stressed senior study author Sophia Kamran, MD, Assistant Professor of Radiation Oncology at Harvard Medical School and Director of Diversity, Equity, and Inclusion in the Department of Radiation Oncology at the Massachusetts General Hospital Cancer Center.
Study Methods and Results
In the new study, the investigators focused on the American Association of Cancer Research’s Project Genomics Evidence Neoplasia Information Exchange (GENIE)—a publicly available, international cancer registry populated with clinically relevant genomic sequencing information. Multiple research organizations have used Project GENIE to describe novel genomic variations between racial categories of different tumors. These discoveries, however, have often conflicted with other findings and have not been amenable to replication or biological explanations.
“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,” explained Dr. Kamran.
To better understand how the Project GENIE tumor landscape related to the broader cancer population, the investigators used the U.S. Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research—data which specially defined the proportion of patients expected from each racial and ethnic group for a given cancer type.
They discovered that White patients were adequately or overly represented for all cancer types except lung cancer and melanoma, and that Asian patients had significant overrepresentation across several tumor types—including colorectal cancer, lung cancer, and breast cancer.
However, Black patients were significantly underrepresented for most cancers, except melanoma and cervical cancer, while Hispanic patients were consistently underrepresented for all cancers. Native American and Pacific Islander populations had zero representation for many cancer types.
Conclusions
The investigators suggested that the reasons behind the low registry representation of Black and Hispanic patients were varied, ranging from ingrained institutional exclusion to mistrust of research agendas by the underrepresented groups themselves. Despite these findings, they expressed hope that greater recognition of the scope of the problem may lead to sustainable improvements.
“Even basic changes in methodology and recruitment for future biorepositories can dramatically improve their ability to address health disparities,” suggested Dr. Kamran. “For instance, standardized methods to obtain demographic information of participants should be implemented by all institutions, and self-identified ethnicities should have more options than the binary ‘Hispanic’ or ‘non-Hispanic’ present in the current [Project] GENIE database,” she concluded.
Disclosure: For full disclosures of the study authors, visit nature.com.
