Impact of concurrent chemotherapy with radiation therapy for elderly patients with newly diagnosed glioblastoma: a review of the National Cancer Data Base.

To investigate the utilization and overall survival (OS) impact of concurrent chemotherapy in combination with radiation therapy (RT) for elderly glioblastoma (GBM) patients. Elderly patients (age >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). The Cochran-Armitage test was used for trend analysis. Hazard ratios (HR) and 95% confidence intervals (CIs) were determined using Cox proportional hazards. Propensity score analysis was performed to reduce selection bias in treatment allocation. A total of 5252 patients were identified (RT alone: n = 1389; ChemoRT: n = 3863). There was increasing utilization of chemotherapy during this period (45-80%, P < .001). A similar trend was also observed for the subset of age >80 (25-68%, P < .001). ChemoRT was associated with significantly better OS than RT alone (HR 0.79, 95% CI 0.70-0.89, P < .001) on multivariate analysis, and similar OS benefit was demonstrated with 1202 pairs of propensity-matched patients (HR 0.79, 95% CI 0.73-0.86, P < .001). For the matched pair, the median OS was 5.8 months with ChemoRT and 5.0 months with RT alone; the 2-year OS rate was 9% with ChemoRT and 4% with RT alone (P < .001). Concurrent chemotherapy has been administered with RT for the majority of elderly GBM patients. Addition of chemotherapy to RT for elderly GBM patients is associated with significantly improve OS in routine clinical practice.