TB-04 TERT PROMOTER MUTATION AS A SUSCEPTIBLE MOLECULAR MARKER OF BCNU LOCAL THERAPY

INTRODUCTION: Alkylating agents, including Temozolomide (TMZ) and CCNU (ACNU) have been widely accepted as a standard treatment in malignant gliomas. Several studies also demonstrated that BCNU wafer placement extended survival in glioblastoma patients. However, little study demonstrated gene-specific efficacy of BCNU local therapy in malignant gliomas. Herein, we investigated BCNU sensitivity for patient-derived primary cultured glioma cells. MATERIALS AND METHODS: From January 2017 to July 2019, 58 gliomas (grade III, IV) were tested genomic analysis and ATP-based cell viability after BCNU treatment. IDH1/2 mutation and TERT promoter mutation status was determined by Sanger sequencing. MGMT methylation status were evaluated by methylation specific PCR. RESULTS: Of 58 cases,10 cases (17.2%) and 32 (55.2%) cases harbored IDH1/2 mutation and TERT mutation (C228T, C250T), respectively. Among them, co-mutation was identified in 5/58 cases (8.6%). MGMT was methylated in 17/58 cases (29.3%). Interestingly, the presence of TERT promoter mutation was positively correlated with BCNU sensitivity, particularly in IDH1/2 wild-type tumors (p<0.05). In contrast, there was no significant relationship between TMZ sensitivity and IDH mutation/MGMT methylation status. CONCLUSION: Although sample size is small, our results imply TERT promoter mutations might be a predictive molecular marker for BCNU sensitivity in malignant gliomas. Since TERT mutations are located at two hot spot loci (C228T and C250T), vast majority of TERT promoter mutations can be evaluated during surgery, which may contribute tailored therapeutic strategy in malignant gliomas.