Columbia University College of Physicians and Surgeons New York, NY
E. M. Ishak1, A. Mercurio2, C. J. Kinslow3, M. Siegelin2, G. M. McKhann4, M. Gallitto3, M. B. Sisti4, J. N. Bruce4, P. Canoll5, F. Iwamoto2, D. P. Horowitz6, A. I. Neugut2, L. A. Kachnic2, S. K. Cheng7, and T. J. C. Wang2; 1Columbia University Vagelos College of Physicians and Surgeons, New York, NY, 2Columbia University, New York, NY, 3Department of Radiation Oncology, Columbia University Irving Medical Center, New York, NY, 4Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY, 5Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, 6Columbia University Irving Medical Center, New York, NY, 7Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY
Purpose/Objective(s): Survival differences for adult glioma patients in the US have been described by race/ethnicity. For example, Hispanic patients have greater survival than white patients, even when controlling for histological diagnosis and treatment. While racial/ethnic differences in targetable driver mutations have been described for cancers of the breast, prostate, lung, and colon, similar large scale efforts to define racial/ethnic differences in gliomas are lacking. To our knowledge, this is the first large institutional study to investigate molecular status in Hispanic patients with World Health Organization grade 2-3 gliomas. Materials/
Methods: We reviewed clinical and molecular data for 129 patients with grade 2-3 gliomas prospectively-enrolled in an observational registry at our institution from 2014 to the present. Clinical and molecular features were compared with a previously published retrospective cohort of 198 patients with glioblastoma treated from 2010 to 2014. We used the chi-square test to determine the association of IDH status with race/ethnicity. The Kaplan-Meier method and Cox proportional hazard regressions were used to assess the association of race/ethnicity and IDH status with progression-free survival (PFS) and overall survival (OS). Results: Following exclusions, we identified 282 patients with molecularly characterized tumors eligible for analysis. This included 31 Hispanic patients and 53 non-Hispanic patients with grade 2-3 gliomas and 55 Hispanic patients and 143 non-Hispanic white patients with glioblastomas. For all patients, we found that 43% (23/53) of profiled tumors from Hispanic patients were IDH-mutant versus 22% (32/143) from non-Hispanic whites (p=0.005). Among patients with grade 2-3 gliomas, 71% (N=22) of profiled tumors from Hispanic patients were IDH mutant versus 60% (N=32) of those from non-Hispanic white patients (p=0.28). The OS and PFS of patients with grade 2-3 gliomas, regardless of IDH status, did not vary significantly when stratified by ethnicity (p=0.44, p=0.94, respectively), however, the majority of patients in both groups had IDH-mutant tumors. No significant survival differences between Hispanic and non-Hispanic white patients were noted in IDH wildtype or mutant tumors. The effect of IDH status on PFS and OS was similar in Hispanic (PFS: HR = 3.93, 95% CI 1.37-11.3, p=0.011; OS: HR = 4.64, 95% CI 1.57-13.7, p=0.006) and non-Hispanic white patients (PFS: HR = 2.77, 95% CI 1.47-5.20, p=0.002; OS: HR=4.51, 95% CI 2.21-9.18, p<0.001). Similar findings were observed when stratifying by 1p19q-codeletion status. Conclusion: Our study demonstrates that Hispanic patients are more likely to harbor IDH-mutant tumors compared with non-Hispanic whites. Prognosis is similar when accounting for IDH status.
