The Role of Extent of Resection in IDH1 Wild‐Type or Mutant Low‐Grade Gliomas. Issue 6 (June 2018)

• Record Type: Journal Article
• Authors: Patel, Toral; Bander, Evan D; Venn, Rachael A; Powell, Tiffany; Cederquist, Gustav Young‐Min; Schaefer, Peter M; Puchi, Luis A; Akhmerov, Akbarshakh; Ogilvie, Shahiba; Reiner, Anne S; Moussazadeh, Nelson; Tabar, Viviane
• Is Part Of: Neurosurgery. Volume 82:Issue 6(2018)
• Publication Date: 2018-06
• Subjects: Extent of resection -- Low‐grade glioma -- WHO grade II glioma -- IDH1 mutation; Nervous system -- Surgery -- Periodicals; 617.48005
• DOI: 10.1093/neuros/nyx265
• Languages: English
• ISSNs: 0148-396X

Abstract

Abstract: BACKGROUND : Maximizing extent of resection (EOR) improves outcomes in adults with World Health Organization (WHO) grade II low‐grade gliomas (LGG). However, recent studies demonstrate that LGGs bearing a mutation in the isocitrate dehydrogenase 1 (IDH1) gene are a distinct molecular and clinical entity. It remains unclear whether maximizing EOR confers an equivalent clinical benefit in IDH mutated (mtIDH) and IDH wild‐type (wtIDH) LGGs. OBJECTIVE : To assess the impact of EOR on malignant progression‐free survival (MPFS) and overall survival (OS) in mtIDH and wtIDH LGGs. METHODS : We performed a retrospective review of 74 patients with WHO grade II gliomas and known IDH mutational status undergoing resection at a single institution. EOR was assessed with quantitative 3‐dimensional volumetric analysis. The effect of predictor variables on MPFS and OS was analyzed with Cox regression models and the Kaplan‐Meier method. RESULTS : Fifty‐two (70%) mtIDH patients and 22 (30%) wtIDH patients were included. Median preoperative tumor volume was 37.4 cm 3 ; median EOR of 57.6% was achieved. Univariate Cox regression analysis confirmed EOR as a prognostic factor for the entire cohort. However, stratifying by IDH status demonstrates that greater EOR independently prolonged MPFS and OS for wtIDH patients (hazard ratio [HR] = 0.002 [95% confidence interval {CI} 0.000‐0.074] and HR = 0.001 [95% CI 0.00‐0.108] respectively) but not for mtIDH patients (HR = 0.84 [95% CI 0.17‐4.13] and HR = 2.99 [95% CI 0.15‐61.66] respectively). CONCLUSION : Increasing EOR confers oncologic and survival benefits in IDH1 wtLGGs, but the impact on IDH1 mtLGGs requires further study.