Clinicopathological Correlation of Glioma Patients with respect to Immunohistochemistry Markers: A Prospective Study of 115 Patients in a Tertiary Care Hospital in North India.

Abstract

Background:With the incorporation of molecular subtyping in glioma patients in 2016 WHO classification, there is a need to understand the immunohistochemistry (IHC) marker expression in various glioma patients and to clinically correlate with various subgroups.Objective:Aim of the study was to assess IHC marker expression profile in glioma patients and to clinically correlate them in various subgroups.Materials and Methods:The prospective study included 115 glioma patients. IHC markers (isocitrate dehydrogenase [IDH] 1, ATRX, P53, Ki-67 antibody) were done in all patients. Patients received treatment as per the grade of tumor. The patients were followed in 3 monthly intervals, for a period of 12 months. SPSS software version 20.0 was used for statistical analysis. Tables were prepared in Microsoft Excel sheet. Kaplan–Meier method was used for survival analysis.Results:There were 11 Grade 1, 33 Grade 2, 26 Grade 3, and 45 glioblastoma multiforme (GBM) patients out of which 10 patients were secondary GBM cases. IDH1 mutation is frequent in Grade 2 and Grade 3 tumors of both astrocytic and oligodendroglia tumors. Its mutation is also common in secondary GBM patients. ATRX mutation is specific to astrocytic lineage, Grade 2, Grade 3, and secondary GBM patients.Conclusion:Molecular nature of DA and AA cases can be accurately confirmed by combined IDH1 and ATRX IHC thereby avoiding costly investigations such as fluorescence in situ hybridization. In astrocytic tumors, p53 can act as a surrogate marker. IDH-mutant glioma patients have better prognoses than IDH wild gliomas.