It is unclear whether the survival difference observed between glioblastoma (GBM), giant cell glioblastoma (gcGBM), and gliosarcoma (GSM) patients is due to differences in tumor histology, patient demographics, and/or treatment regimens. The USA National Cancer Database was utilized to evaluate patients diagnosed with GBM, gcGBM, and GSM between 1998 and 2011. Kaplan-Meier survival estimates and Cox proportional hazards models were utilized to estimate overall survival. A cohort of 69,935 patients was analyzed; 67,509 (96.5%) of these patients had GBM, 592 (0.9%) gcGBM, and 1834 (2.6%) GSM. The median age for GBM and GSM patients was 61 versus 56 years for gcGBM (p<0.0001). Higher extent of resection (p<0.0001) and radiation (p=0.001) were observed in gcGBM patients compared to other histologies. Multivariate analysis showed that gcGBM patients had a 20% reduction in the hazards of mortality (hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.69-0.93) compared to GBM, while GSM patients trended towards higher hazards of mortality (HR 1.04, 95% CI 0.96-1.12) than the GBM cohort. Previous studies have suggested a disparity in the survival of patients with GBM tumors and their histological variants. Using a large cohort of patients treated at hospitals nationwide, this study found a 20% reduction in the hazards of mortality in gcGBM patients compared to GBM. Similarly, gcGBM patients had a 24% reduction in the hazards of mortality compared to the GSM cohort. GSM patients had a 3% increase in the hazards of mortality compared to GBM.
Keywords: Chemotherapy; Giant cell glioblastoma; Glioblastoma; Gliosarcoma; Overall survival.
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