[Prognostic value of TERT mutation in adults with primary glioblastomas. Preliminary results]

Glioblastoma (GB) is one of the most aggressive primary brain tumors. Analysis of molecular genetic factors affecting prognosis in patients with GB is an important direction of fundamental and clinical researches. There are literature data on the effect of TERT gene mutations, MGMT methylation and IDH1/2 status on overall survival in patients with GB.

To evaluate the incidence of TERT gene promoter mutations in adults with primary GB and to analyze the effect of TERT mutations on relapse-free and overall survival, as well as interaction of these mutations with MGMT gene methylation and IDH1/2 mutations.

The study included 56 patients (26 women and 30 men) with histologically verified GB in which genetic and molecular investigations were performed. There were patients with life duration >3 years (n=15) and people with an extremely unfavorable course of disease (14 ones with primary multiple GB, 8 patients with GB metastases including extraaxial and 8 patients with life duration <8 months). TERT gene sequencingwas performed in all the cases, IDH1/2 status was known for 41 patients, MGMT status - for 23 patients.

Overall survival significantly differed between patients with and without TERT mutation (56 vs 17 months, p>0.05). TERT gene promoter mutation increased the effect of IDH1/2 mutations on overall and relapse-free survival (p=0.011). No TERT and IDH1/2 gene mutations worsened prognosis. There were no significant differences between TERT status and development of primary multiple GBs, as well as extra- and intracranial metastases.

Thus, the combined status of IDH1/2 and TERT mutations was a factor of better prognosis and can be proposed in clinical practice.