Biopsy versus Surgical Resection for Glioblastoma in the Elderly: A Large Propensity Score-matched Retrospective Analysis

Introduction: Glioblastoma (GBM) is a primary brain tumor with a poor prognosis and a significant incidence among elderly patients. While observational studies have demonstrated improved clinical outcomes with maximal safe surgical resection, the only randomized trial comparing biopsy and resection has suggested a lack of overall survival benefit for elderly patients. This study aims to evaluate the effect of biopsy versus surgical resection on overall survival in a propensity score-matched cohort of elderly patients with accessible IDH-wild-type GBMs.

Methods: Data were extracted from the SEER (Surveillance, Epidemiology, and End Results) database, covering GBM cases diagnosed from 2000 to 2020 in elderly (65–79 years) and super-elderly (80+ years) populations. Patients were categorized by treatment type. Nearest-neighbor propensity score matching (PSM) was employed to balance demographics and clinical factors. Overall survival (OS) was assessed through Kaplan-Meier curves, log-rank tests, and Cox multivariate analyses.

Results: A total of 3,380 patients were included, with 336 receiving biopsy only, and 3,044 undergoing surgical resection (1,534 subtotal, 1,451 gross total, & 59 partial). The cohort was 44% female, predominantly white (80.83%), and mostly aged 65-74 years old (64.94%). Before PSM, the surgery cohort showed a median OS of 6 months, compared with 4 months for the biopsy group (log-rank p< 0.0001). PSM yielded 336 matched pairs and confirmed a significantly higher median OS for surgical (7.5 months) patients versus biopsy (4 months) patients (log-rank p< 0.0001). Cox multivariate analysis also affirmed treatment type as an independent predictor of OS (adjusted HR 0.68, 95% CI 0.58-0.80, p< 0.0001).

Conclusion : In elderly GBM patients, surgical resection was associated with improved overall survival compared to biopsy, highlighting the potential benefit of intervention. Limitations due to data availability prevented the analysis of progression-free survival. Future clinical trials are necessary to clarify optimal treatment regimens for this population further.