LAUSR

PURPOSE Glioma incidence is 25% lower in Hispanics than White non-Hispanics. The U.S. Hispanic population is diverse, and registry-based analyses may mask incidence differences associated with geographic/ancestral origins. METHODS County-level glioma incidence data in Hispanics were retrieved from the Central Brain Tumor Registry of the United States (CBTRUS). American Community Survey data were used to determine county-level proportion of the Hispanic population of Mexican/Central-American origin and of Caribbean origin. Age-adjusted incidence rate-ratios and incidence rate ratios (IRRs) quantified the glioma incidence differences across groups. State-level estimates of admixture in Hispanics were obtained from published 23andMe data. RESULTS Compared to predominantly Caribbean-origin counties, predominantly Mexican/Central-American-origin counties had lower age-adjusted risks of glioma (IRR=0.83; P<0.0001), glioblastoma (IRR=0.86; P<0.0001), diffuse/anaplastic astrocytoma (IRR=0.78; P<0.0001), oligodendroglioma (IRR=0.82; P<0.0001), ependymoma (IRR=0.88; P=0.012), and pilocytic astrocytoma (IRR=0.76; P<0.0001). Associations were consistent in children and adults, and using more granular geographic regions. Despite having lower glioma incidence, Hispanic glioblastoma patients from predominantly Mexican/Central-American-origin counties had poorer survival than Hispanics living in predominantly Caribbean-origin counties. Incidence and survival differences could be partially explained by state-level estimates of European admixture in Hispanics, with European admixture associated with higher incidence and improved survival. CONCLUSIONS Glioma incidence and outcomes differ in association with the geographic origins of Hispanic communities, with counties of predominantly Mexican/Central-American-origin at significantly reduced risk and those of Caribbean-origin at comparatively greater risk. Although typically classified as a single ethnic group, appreciating the cultural, socioeconomic, and genetic diversity of Hispanics can advance cancer disparities research.