Brain tumor study highlights differences among Hispanics

Although usually classified as a single ethnic group, people of Hispanic heritage have significantly different risks for brain tumors based on their geographic origin, suggesting greater diversity that warrants attention in the health care setting.

Insight-published in the journal Neuro-oncology by a team of researchers at Duke Health—resulted from an analysis of glioma brain tumors, which are known to be less prevalent among people of Hispanic heritage compared to non-Hispanic white people.

The researchers confirmed the ethnic difference in glioma incidence, but identified a gap within the Hispanic group that had not been previously exposed. Notably, populations that trace their heritage to the Caribbean had higher rates of fatal brain tumors than those from Mexico or Central America.

“Cancer registries record Hispanic ethnicity with a single yes-no value, but US Hispanics can trace their heritage to different geographic regions and are culturally and genetically diverse,” said lead author Kyle Walsh, Ph .D., associate professor in the Department. of Neurosurgery at Duke University School of Medicine.

“We hypothesized that previous studies about gliomas—and potentially other diseases—could mask differences in incidence and outcomes if they relied on the limited information provided in cancer registries.”

Walsh and colleagues — including senior author Quinn T. Ostrom, Ph.D., assistant professor of neurosurgery at Duke — analyzed data from the U.S. Census Bureau and the United States Central Brain Tumor Registry.

The researchers found a relatively high incidence of gliomas in Hispanics from Cuba, Puerto Rico, the Dominican Republic and other areas of the Caribbean.

While their glioma incidence rate was still lower than for non-Hispanic whites, Caribbean Hispanic groups had a significantly higher rate than that found among Hispanics from Mexico and Central America.

The researchers found, however, that Hispanics of Mexican or Central American descent tended to have worse outcomes from gliomas than those from the Caribbean.

“These differences appear to be partially attributable to ancestry-related genetic differences among US Hispanic populations,” Walsh said.

Historically, Walsh noted, Europeans and Africans arrived in much greater numbers in the Caribbean regions than in Central America, intermingling over time with native island populations and potentially bringing higher glioma risk.

While greater European ancestry is associated with a higher risk of glioma, African ancestry has been associated with better survival outcomes. In the Caribbean region, where enslaved people from Africans arrived in large numbers, populations inherited the highest incidence of glioma from European ancestry, along with the improved survival trend from African ancestry.

Walsh said structural and economic factors likely also contribute, particularly affecting patient survival.

“We demonstrate that recognizing and properly accounting for the cultural, socioeconomic, and genetic diversity that exists within American Hispanics is imperative when examining cancer disparities,” Walsh said.