LAUSR

BACKGROUND AND OBJECTIVE Several studies have examined the prognostic significance of IDH1/2 mutation, 1p/19q codeletion and MGMT promoter methylation in lower-grade gliomas but most of these used the 2007 fourth edition of the WHO classification. We evaluate prognostic significance of these indicators in the 2016 WHO updated fourth edition of CNS tumor classification. METHODS A total of 180 intracranial glioma patients diagnosed according WHO 2016 edition between December 2016 and December 2018 Jinling Hospital (Nanjing, China) were reviewed retrospectively. We performed survival analysis on 109 patients with complete molecular pathology and follow-up data. RESULTS Histologically, 52 were diagnosed as astrocytoma (WHO grade II and III), 17 as oligodendrogliomas (WHO grade II and III) and 40 as GBMs. At last follow-up, 50.5% patients had experienced tumor progression and 34.9% had died. Among grade II and III cases 36.2% experienced tumor progression and 27.5% died. In univariate Kaplan-Meier analysis, multifocal tumor, EGFR mutation or amplification, PIK3CA mutation and IDHwt/TERTpwt group were associated with shorter PFS (p < 0.001, p = 0.003, p = 0.005, p < 0.001, respectively) and OS (p = 0.010, p = 0.020, p = 0.018, p < 0.001, respectively) as were older age (≥55 years), multifocal tumor, IDH1/2 wild type, 1p/19q non-codeletion and negative methylation in the MGMT promoter region. A Cox proportional hazards model was created demonstrating that single tumor (HR = 0.180, p = 0.04), MGMTp methylation (HR = 0.095, p = 0.003) and chemoradiotherapy (HR = 0.006, p = 0.002) were independent prognostic factors for OS. CONCLUSIONS Beyond histological classification as well as IDH1/2 mutation, 1p/19q codeletion status, we could incorporate IDH1/2mt combined with TERTpmt, EGFR mutation or amplification and PIK3CA mutation into the diagnostic criteria for DLGGs to supplement WHO 2016 pathological criteria.