IDH mutation and MGMT methylation status in glioblastoma and other gliomas patients: a Russian retrospective cohort study.

Glioma is a devastating type of brain tumor with high malignancy, an extremely high mortality rate, and a recurrence risk. Molecular markers are known to have a major role in classification, prognosis, survival rate, and therapy determination for different glioma subtypes. The aim of this study was to investigate the association of gliomas' main genetic markers: isocitrate dehydrogenase (IDH) mutations and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status with the survival rate in Russian patients with glioblastoma and other glial tumors. According to histological subtype, included glioma patients were divided into two groups: glioblastoma (n = 90) and other gliomas (n = 40). IDH mutations were screened by high-resolution melting-curve analysis (HRM) followed by direct sequencing, and MGMT methylation was detected with pyrosequencing. Our data showed that IDH mutations are significantly more frequent among patients with other gliomas compared to glioblastoma patients (p < 0.001). Patients with mutated IDH gene have a significantly higher progression-free survival (PFS) and overall survival (OS) rates than those with wild-type genes. MGMT promoter methylation status was found to be significantly associated with PFS, but not OS. The presence of IDH mutation with a methylated MGMT promoter significantly increased patients' PFS and OS. To our knowledge, this is the first study to investigate the association of IDH and MGMT genetic biomarkers with glioma in the Russian population. Our findings could be used in future studies to improve glioma prognosis and classification and reach a personalized treatment protocols depending on multiple molecular biomarkers.