Role of Ethnicity and Geographic Location on Glioblastoma IDH1/IDH2 Mutations.

Abstract Background Previous studies have demonstrated possible differences in glioblastoma (GBM) survival attributable to ethnicity. The goal of this study was to quantify oncogenic differences and evaluate the overall survival (OS) and progression-free survival (PFS) differences in GBM patients across race/ethnicity using both population-based surveillance and institutional datasets from United States (US) and Mexico. Methods Retrospective cohort study comprising the Texas Cancer Registry (TCR, N=4134) and referral institutions located in US (N=254) and Mexico (N=47) were evaluated. Primary outcomes include OS and PFS. Oncogenic differences attributable to ethnicity were assessed. IDH1/IDH2 status was evaluated by sequencing in US and Mexico samples. Kaplan-Meier and Cox proportional-hazards regression for survival analysis. Results 4134-GBM patients were identified from the TCR dataset, ethnicity comparison demonstrated that Hispanics were diagnosed at a significantly younger age compared to non-Hispanic whites (NHW) (median: 58 vs. 62, p Conclusions IDH2 mutations are more prevalent in Mexican Hispanics compared to US patients and may be a crucial contributor to the previously reported survival benefit of Hispanics in large population databases. These findings are critical for both screening of IDH2 mutations and targeted interventions in GBM.