Glioblastoma (GBM) is the most common brain tumor in adults with a poor prognosis and predominantly astrocytic differentiation. GBM is classified according to the isocitrate dehydrogenase (IDH) mutation according to the World Health Organization (WHO) Brain Tumors 2016 classification. IDH-1 gene mutations are evaluated immunohistochemically (IHC) and molecular methods in current pathology laboratory practice.
The aim of this study was to determine the overall survival in GBM cases according to IDH-1 mutation status and Ki-67 proliferation index.
Total of 53 patients diagnosed as GBM between 2007-2020 in Sivas Cumhuriyet University Faculty of Medicine, Department of Pathology were evaluated. Disease-free median survival of 7 (13%) GBM patients with IDH mutation was 2 months (2-year survival 14%), disease-free median survival 9 months (2-year survival 24 %) in GBM IDH-wild type cases. In cases with a higher Ki-67 proliferation index, the median disease-free survival were shorter.
In conclusion statistically significant results could not be obtained between disease-free survival in GBM IDH-mutant type and GBM IDH-wild type. However, the mean Ki-67 proliferation index of GBM IDH-wild type cases was found to be much higher than GBM IDH-mutant cases. High Ki-67 proliferation index was found to be associated with a significantly shorter survival.