Extent of Resection and Survival in Glioblastoma: Clinical and Pathological Correlates: A Systematic Review and Meta-Analysis

Abstract

Background: Glioblastoma is the most aggressive primary malignant brain tumor in adults and is associated with poor prognosis despite advances in surgical and adjuvant therapies. Extent of resection (EOR) has emerged as a critical prognostic factor influencing survival outcomes; however, the optimal degree of tumor removal and its relationship with clinical and pathological characteristics remain controversial. Objective: To systematically evaluate the impact of extent of resection on overall survival (OS) and progression-free survival (PFS) in patients with glioblastoma and to assess associated clinical and pathological correlates. Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched for eligible studies published from 2000 to 2026. Studies comparing survival outcomes according to extent of resection, including gross total resection (GTR), subtotal resection (STR), supramarginal resection (SMR), and biopsy, were included. Data extraction and quality assessment were independently performed by two reviewers. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using random-effects models, and heterogeneity was assessed using the I² statistic. Results: A total of [number] studies involving [number] patients with glioblastoma were included. Compared with STR or biopsy, GTR was significantly associated with improved OS (pooled).