10002- MPC-1 HISTOLOGICAL GRADE AND TP53 MUTATIONS STRATIFY PROGNOSIS IN MOLECULAR GLIOBLASTOMA

Abstract BACKGROUND In the 2021 WHO Central Nervous System tumor classification, the Glioblastoma, IDH-wildtype diagnosis has changed markedly. We compared the clinical backgrounds and prognoses of molecular glioblastoma (mGBM) and conventional glioblastoma (histological glioblastoma, hGBM) in a Japanese cohort. METHODS We included 274 patients with glioblastoma who were treated at five institutions from 2011 to 2023. Driver gene analysis was performed using a brain tumor-specific custom gene panel to verify the association between molecular and clinical information. RESULTS Patients with mGBM had a better preoperative KPS, lower Ki-67, and lower removal rates than did those who had hGBM. Overall survival was longer in patients with mGBM than in those with hGBM (1207 vs 598 days, p = 0.032). TP53 mutation (hazard ratio: 5.33, 95% confidence interval: 0.26 - 108.7, p = 0.012) and histological grade 3 (p = 0.045) were significant poor prognostic factors in mGBM. CONCLUSION Patients with mGBM had better preoperative KPS, worse removal rates, lower Ki-67 labeling index, and better overall survival than did those with hGBM. Additionally, histological grade of mGBM is potentially useful for estimating prognosis. Glioblastoma in the WHO CNS5 2021 remains a heterogeneous population, and prognostic stratification based on the patient’s clinical background and molecular information is desirable.