Extent of resection and survival outcomes of geriatric patients with glioblastoma: Is there benefit from aggressive surgery?

Objective: We examine the impact of age and extent of resection (EOR) on overall survival (OS) in geriatric patients with Glioblastoma (GBM). Methods: The SEER 18 Registries was used to identify patients aged 65 and above with GBM from 2000-2016. Patients were categorized into 4 groups based on EOR: Biopsy/Local Excision (B/LE), Subtotal Resection (STR), Gross Total Resection (GTR), and Supratotal Resection (SpTR). Primary endpoint was OS, which was calculated using the Kaplan-Meier method and analyzed by the Log-rank and Wilcoxon-Breslow-Gehan test. Multivariable Cox proportional hazards regression model was utilized to identify factors associated with OS. Likelihood of undergoing SpTR was explored using a multivariable logistic regression model. Results are given as median [IQR] and HR [95 % CI]. Results: Among 17,820 geriatric patients with GBM, median age was 73 years [68-78], 44 % were female, 91 % White, and 8% Hispanic. SpTR was performed in 2907 (16 %), GTR was performed in 2451 (14 %) patients, STR in 4879 (28 %), and B/LE in 7396 (42 %). There was a decline in the proportion of patients treated with SpTR with advancing age (65-69 years, 17 % vs 95+ years, 0%; p < 0.0001), and older age corresponded with a decrease in the odds of undergoing SpTR. In survival analysis, GTR (HR 0.61 [0.58-0.65]) and SpTR (HR 0.65 [0.62-0.68]) were associated with improved survival, even in octogenarian patients. Conclusions: These findings suggest that aggressive surgical resection is associated with improvement in OS in geriatric patients. These results emphasize that age should not influence surgical strategy, as there is a survival benefit from maximal resection in geriatric patients.