SURGICAL RESECTION VERSUS BIOPSY WITH ADJUVANT THERAPY FOR HIGH GRADE GLIOMA: A SYSTEMATIC REVIEW AND META-ANALYSIS OF OVERALL SURVIVAL, PROGRESSION-FREE SURVIVAL, AND FUNCTIONAL OUTCOMES
Keywords:
High-grade glioma, glioblastoma, surgical resection, biopsy, overall survival, progression-free survival, functional outcomes, meta-analysis.Abstract
Background It is difficult to differentiate the benefit of surgical resection from choice of treatment and inherent functional differences for high-grade glioma.
Objectives To compare overall survival (OS), progression-free survival (PFS) and functional outcome between resection and biopsy in adults with postoperative adjuvant therapy or those under consideration for postoperative adjuvant therapy.
Methods The searches were performed in PubMed, Europe PMC and ClinicalTrials.gov from their inception until 11 October 2026. Eligible were original studies with an accessible original PDF. The screening, extraction and appraisal were carried out using AI but not by humans. Pooled restricted maximum-likelihood random-effects models with modified Hartung–Knapp confidence intervals were used to adjust hazard ratios (HRs). Evidence was analyzed separately by random and different surgical contrasts.
Results 267 reports were assessed with 88 reports from 82 study families included. Four cohorts of patients with glioblastoma who received radiotherapy (517 patients) were included in the main analysis. Any resection was associated with longer OS than biopsy (HR 0.46, 95% CI 0.32–0.66; I²=0%). Exploratory complete-resection analyses favoured surgery for OS across 10 cohorts (HR 0.47, 95% CI 0.38–0.57; I²=15.8%) and PFS across five cohorts (HR 0.53, 95% CI 0.31–0.89; I²=62.3%). One randomized trial reported no OS difference, and a preference for resection for PFS. There was a wide range of functional outcomes, which were not pooled. Very low certainty of observational evidence (provisional). Evidence coverage was not possible due to 484 unretrieved reports and 19 PDF-availability exclusions.
Conclusion Observational glioblastoma cohorts have indicated that resection is linked to longer survival, but this is confounded and retrieval limitations make it challenging to make causal inferences. The benefits and functional advantages of randomized OS are still unknown.
