Determination of

BACKGROUND/

aimThe most frequent and dangerous kind of primary brain tumor is glioblastoma multiforme (GBM). The survival rates associated with GBM are very short and molecular markers for predicting survival are needed. The aim of our study was to evaluate isocitrate dehydrogenase 1 and 2 (IDH1, IDH2), telomerase reverse transcriptase (TERT), O-6- methylguanine-DNA methyltransferase (MGMT) and alpha-thalassemia/mental retardation, X-linked (ATRX) genes with next-generation sequencing (NGS) to find potential pathological mutations and their effect on survival. MATERIALS AND

methodsThirty patients who had undergone craniotomy and were diagnosed with high-grade glioma were evaluated for this study. Peripheral blood samples were obtained from all participants. IDH1, IDH2, TERT, MGMT and ATRX genes were evaluated with next-generation sequencing from the samples. Survival analysis evaluated the effects of all these mutations on survival.

resultsThe median age of the patients was 58.5 (range=11- 74) years, and 56.7% (n=17) were under 60 years of age. According to sex, male patients comprised 66.7%. Targeted NGS detected 21 chromosomal aberrations. When more than three chromosomal anomalies were accepted as a reference, anomaly in three or fewer chromosomes negatively affected overall survival (hazard ratio=2.83).

conclusionTargeted NGS generates therapeutically meaningful information, providing better prognostic information than conventional histology. Our study shows that NGS provides important information on survival by helping to detect chromosomal changes that can be detected in routine blood samples. It is clear that incorporating molecular diagnostics into our standard-of-care routine will help us better understand our patients' outcomes.