NCOG-11. EXTENT OF RESECTION OF CONTRAST-ENHANCING AND NON-ENHANCING TUMOR: DIFFERENT IMPACTS ON SURVIVAL ACCORDING TO TYPES OF ADULT-TYPE DIFFUSE GLIOMAS IN 2021 WHO CLASSIFICATION

Abstract BACKGROUND To evaluate the impact of extent resection (EOR) contrast-enhancing (CE) and nonenhancing (NE) tumors in types adult-type diffuse gliomas according to 2021 WHO classification. METHODS Total 1,196 glioma patients diagnosed between 2001 from a single institution were enrolled (183 with isocitrate dehydrogenase [IDH]-mutant 1p/19q codeleted oligodendroglioma [herein oligodendroglioma], 211 IDH-mutant astrocytoma, 802 IDH-wildtype glioblastoma). Analyses performed within each type assess predictors overall survival, including clinical, imaging data, histological grade, O6-methylguanine-methyltransferase (MGMT) promoter methylation status, adjuvant treatment, EOR CE NE tumors. Subgroup analyses tumor. RESULTS Among patients, 926 (77.4%) had In oligodendrogliomas, gross total removal (GTR) tumor was associated survival (hazard ratio [HR]=0.09, P< 0.001), whereas GTR not (HR=0.41, P=0.088). 81 (43.3%) tumor, only independent predictor (HR=0.20, P=0.092) multivariable analysis. independently better astrocytoma glioblastoma (all Ps< 0.05). CONCLUSIONS both may significantly improve all except oligodendrogliomas. be crucial survival; aggressive unnecessary, is recommended.