Impact of Extent of Surgical Resection on Survival in World Health Organization Grade 4 Gliomas: A Molecular Subtype-Based Analysis

Background Extensive surgical resection is associated with longer survival in patients with glioma; however, the combined impact of surgical extent and molecular pathology on prognosis remains unclear. In this study, we evaluated how molecular pathology and clinical features influence surgical outcomes in patients with World Health Organization (WHO) grade 4 gliomas, including isocitrate dehydrogenase (IDH)-mutant astrocytomas and IDH wild-type glioblastomas. Methods Data from 501 patients with WHO grade 4 gliomas who underwent surgery were obtained from the Chinese Glioma Genome Atlas database (2005–2019). The effect of resection extent on overall survival was analyzed and stratified using molecular pathology and clinical characteristics. Survival differences were assessed using the Kaplan–Meier method and the Log-rank test, and prognostic factors were identified through univariate and multivariate analyses. Results The extent of resection significantly influenced survival, but its impact varied by molecular subtype. In WHO grade 4 IDH-mutant astrocytomas, gross total resection (GTR) did not confer a significant survival advantage over subtotal resection (STR). Among glioblastoma patients, those with non-methylated O-(6)-methylguanine-DNA methyltransferase promoters and preoperative Karnofsky Performance Status ≤80 showed no significant benefit from GTR compared to STR, whereas GTR substantially prolonged survival in other subgroups. Conclusions The survival benefits of extensive resection vary among patients with WHO grade 4 glioma. Molecular pathology and clinical characteristics should be considered in surgical planning. A conservative approach may be appropriate for some patients; nevertheless, a more aggressive strategy may optimize survival and quality of life for others.