Trends In Utilization And Impact Of Concurrent Chemotherapy With Radiation Therapy For Elderly Patients With Newly Diagnosed Glioblastoma: A Review Of The National Cancer Data Base.

2034Background: To investigate the utilization and overall survival (OS) impact of concurrent chemotherapy in combination with radiation therapy (RT) for elderly glioblastoma (GBM) patients. Methods: Elderly patients (age u003e 70) with supratentorial and nonmetastatic GBM who received RT of 20-75 Gy with concurrent single-agent chemotherapy (chemoRT) or without (RT alone) during 2004-2012 were identified from the National Cancer Data Base (NCDB). RT fractionation was evaluated for those who received standard-fractionated RT (SFRT) or abbreviated hypo-fractionated RT (HFRT). Hazard ratios (HR) and 95% confidence intervals (CIs) were determined using Cox regression analysis. OS rates were determined using the Kaplan-Meier method and compared using the log-rank test. Propensity score analysis was performed to reduce selection bias in treatment allocation. Results: A total of 5,252 patients were identified (RT alone: n = 1389; chemoRT: n = 3863). There was increasing utilization of chemotherapy since 2004, which...