Immunohistochemical Study of IDH1, p53, and Ki67 in Gliomas at a Tertiary Care Centre in India

Background: Gliomas are the most common primary CNS tumor, accounting for 81% of all malignant intracranial tumors. The incidence rate of gliomas varies considerably according to sex, race, and nationality. The use of biomarkers such as IDH1/2 and MDM2 status is becoming increasingly common in the West. Most of the information regarding these molecular alterations in gliomas is derived from Western literature. Minimal data is available involving these molecules in glial tumors among the Indian population. This study will help estimate the frequency of these molecular alterations in gliomas in the Indian population. Materials and Methods: In this prospective study, 60 histopathologically proven cases of gliomas were taken. Representative sections were taken from the tumor area, wax blocks were prepared, and IHC (IDH1, p53, Ki67) was performed. Results: Out of 60 cases, there were 35 (58.3%) males and 25 (41.7%) females. The maximum number of cases was observed in the 6th decade. Glioblastoma multiforme was the most common histological subtype with 23 cases (38.3%), followed by Diffuse Astrocytoma with 16 cases (26.7%). A correlation between various histological subtypes and the grade of glial tumors with IDH1 immunoexpression was found to be highly significant [p<0.001]. A correlation between various histological subtypes and the grade of glial tumors with the Ki67 score was found to be highly significant [p<0.001]. A correlation between various histological subtypes and p53/IDH1 expression, as well as various histological grades and p53/IDH1 expression, was found to be significant [p=0.006,p<0.001]. Conclusion: Our study showed a statistically significant correlation between various histological subtypes and grades of gliomas with p53/IDH1.