Though evidence has been building that scientists could be missing crucial clues about disease etiology as a result of the failure to include diverse populations in genome studies, there are new data to suggest that when investigators overlook distinct subgroups of populations within minority cohorts, they also risk overlooking the detection of some crucial population-specific trends that could inform not just cancer prevalence, but also cancer mortality within certain communities.
In addition to a dearth of precision oncology data on minority patient populations, there are also gaps in the research chronicling the subtle differences between minority groups, argued a group of researchers from Florida’s Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, in an article published in Cancer Epidemiology, Biomarkers & Prevention.
The researchers sought to determine if teasing out differences in cancer mortality within specific subgroups of a larger “minority” cohort could shed light on what types of cancers are especially deadly for each subcohort.
Using New York as a microcosm of cancer diversity, the researchers reviewed cancer death data from 2008 to 2014 retrieved from the New York State Department of Health, including the examination of 245,582 death certificates listing cancer as the official cause of mortality.
Patients were categorized as Hispanic, non-Hispanic white (NHW), non-Hispanic black (NHB), or Asian. The Hispanic and NHB populations were segmented even further to identify if individuals were Puerto Rican, Dominican, South American, Central American, United States-born black, or Caribbean-born black. Though the investigators reported deaths from all cancers for each of these groups, they had a specific goal in mind of revealing cohort-specific patterns of death attributable to liver cancer.
Some striking race-specific observations about cancer mortality were revealed by the research team. They determined that lung cancer was the leading cause of death from all cancers across all racial and ethnic groups in New York (except for black individuals born in the Caribbean and for those from Central America). The third leading cause of cancer mortality across most of the groups was colorectal cancer.
Most notably, Puerto Rican and NHB men were determined to be at a particularly heightened risk of dying from liver cancer compared with non-Hispanic white individuals in New York. Although it is well understood that liver cancer “disproportionately impacts minority populations” — risk of death from this cancer was between 1.5 and 2 times higher in minorities that in NHWs — the death rates from liver cancer seen in these specific subgroups were higher than in all other analyzed populations.
More deaths from liver cancer among NHB and Puerto Rican men can be explained by the increased incidence of hepatitis C in these two groups. However, neither Hispanics as a whole nor Puerto Ricans specifically “are recognized as priority populations in the National Viral Hepatitis Action Plan,” according to the researchers.