Combined-modality therapy with radiation and chemotherapy for elderly patients with glioblastoma in the temozolomide era: A national cancer database analysis

IMPORTANCE The optimal management for elderly patients with glioblastoma (GBM) is controversial. Following maximal safe resection or biopsy, accepted treatment paradigms for elderly patients with GBM include combined-modality therapy (CMT) with both radiotherapy (RT) and chemotherapy (CT), RT alone, and CT alone. OBJECTIVE To evaluate the overall survival (OS) outcomes associated with RT, CT, and CMT for elderly patients with GBM in the modern temozolomide era. DESIGN, SETTING, AND PARTICIPANTS In this retrospective cohort study of a prospectively maintained, multi-institutional national cancer registry, the National Cancer Database was queried for elderly patients (65 years) with newly diagnosed GBM from January 1, 2005, through December 31, 2011, with complete data sets for RT, CT, tumor resection, Charlson-Deyo comorbidity scores, age, sex, and year of diagnosis. Data analysis was performed from October 2015 through December 2015. INTERVENTIONS Combined-modality therapy, RT, CT. MAIN OUTCOMES AND MEASURES Survival by treatment cohortwas estimated using the Kaplan-Meier method and analyzed using the log rank test, univariate and multivariate Cox models, and propensity score-matched analyses. RESULTS A total of 16 717 patients (median [range] age, 73 [65-90 y]; 8870 [53%] male) were identified. The median OS by treatment was 9.0 (95%CI, 8.8-9.3) months with CMT (8435 patients), 4.7 (95%CI, 4.5-5.0) months with RT alone (1693 patients), 4.3 (95%CI, 4.0-4.7) months with CT alone (1018 patients), and 2.8 (95%CI, 2.8-2.9) months with no therapy (5571 patients) (P < .001). On multivariate analysis, CMT was superior to both CT alone (hazard ratio, 1.50 [95%CI, 1.40-1.60]; P < .001) and RT alone (hazard ratio, 1.47 [95% CI, 1.39-1.55]; P < .001), whereas no differences were observed between CT alone vs RT alone (P = .60). Propensity score-matched analyses redemonstrated improved OS with CMT over CT alone (P = .002) and RT alone (P < .001); no differences were observed between CT alone vs RT alone (P = .44). On subgroup analyses, a consistent OS advantage was observed with CMT over both CT alone and RT alone across each age stratification (65-69, 70-74, 75-79, and 80 years) and among patients treated with or without tumor resection (all P < .001). CONCLUSIONS AND RELEVANCE In this analysis of multimodality therapy for elderly patients with GBM, OS was superior with CMT compared with CT alone and RT alone. Survival was similar between CT alone and RT alone, and both CT alone and RT alone were superior to no therapy. This analysis supports the use of CMT for suitable elderly candidates.