Clinical implications of TERT promoter mutation on IDH mutation and MGMT promoter methylation in diffuse gliomas

Abstract

IDH mutation and MGMT promoter methylation are reliable prognostic and predictive biomarkers in grade II-IV diffuse gliomas. Recurrent mutations in the promoter region of the telomerase reverse transcriptase (TERTp) gene have also been found in diffuse gliomas. However, the prognostic and predictive effects of TERTp mutation on IDH or MGMT status are largely unknown. IDH1/2 and TERTp mutations, as well as MGMT methylation statuses, were examined via peptide nucleic acid-mediated PCR clamping and MGMT methylation-specific PCR in 67 paraffinized tumor samples, respectively. TERM mutation was associated with older patients (>= 60 years) and frontally located gliomas. Old age, frontal location, and grade IV were found to be predictive factors of TERTp mutation. TERTp mutation resulted in poor prognosis in overall diffuse gliomas. TERTp mutation was not correlated with overall survival (OS) or progression-free survival (PFS) in the diffuse gliomas. However, TERTp mutations, in combination with MGMT methylation or IDH mutation, showed that there were statistical significant survival differences between MGMT-unmethylated/TERTp-mutated and MGMT-unmethylated/TERTp-wildtype subgroups in grade II gliomas. There was a statistical significant survival difference of OS between IDH-wildtype/TERTp-mutated and IDH-mutated/TERTp-mutated subgroups in grade III gliomas. No significant associations between survival and MGMT/TERTp or IDH/TERTp status were found in grade IV gliomas. In conclusion, the combination of TERTp with IDH or MGMT status may be a prognostic indicator depending on grades.