Effect of Extent of Resection on Survival of Patients with Glioblastoma, IDH–Wild-Type, WHO Grade 4 (WHO 2021): Systematic Review and Meta-Analysis

Background: In light of the recently updated World Health Organization (WHO) 2021 central nervous system tumor classifications, the aim of the present study was to establish the effect of the resection extent on overall survival (OS) and progression-free survival (PFS) for patients who met the current diagnostic criteria for glioblastoma, isocitrate dehydrogenase (IDH)–wild-type (WT), WHO grade 4. Methods: A systematic literature search was performed using the following databases: PubMed, Web of Science, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews and ClinicalTrials.gov to identify studies that had compared OS and PFS after gross total resection (GTR) versus subtotal resection (STR) or biopsy for glioblastoma IDH-WT. Results: We identified 1439 studies, of which 9 met the inclusion and/or exclusion criteria. Of the 2023 patients, 788 had undergone GTR. The meta-analysis showed a significant increase in the OS and PFS duration after GTR for glioblastoma IDH-WT, with a median OS of 20 months (95% confidence interval [CI], 17–25) after GTR versus 12 months (95% CI, 9–15) after STR (P < 0.0001). The median PFS was 11 months (95% CI, 9–12) after GTR versus 7 months (95% CI, 5–7) after STR (P < 0.0001). GTR was associated with a 51% reduction in the mortality risk (hazard ratio, 0.49; 95% CI, 0.36–0.65) and a 42% reduction in the progression risk (hazard ratio, 0.58; 95% CI, 0.39–0.88) compared with STR. Conclusions: The results from our systematic review suggest that GTR is associated with improved OS and PFS compared with STR for glioblastoma, IDH-WT, WHO grade 4 (WHO 2021). However, our findings were limited by the various study designs and significant clinical and methodologic heterogeneity among the studies.