IMMUNOHISTOCHEMICAL ANALYSIS OF IDH1, p53 AND ATRX IN DIFFUSE GLIOMAS AND THEIR CORRELATION WITH CLINICAL AND HISTOLOGICAL PARAMETERS.

Background: Diffuse gliomas account for more than half of all central nervous system (CNS) tumours. The 2016 WHO update of CNS neoplasms incorporates histomorphological as well as molecular features of diffuse gliomas for their categorization. The present study aimed to evaluate the immunohistochemical expression of IDH1, p53 and ATRX mutations in diffuse gliomas and to correlate their expression with clinical and histological parameters. All adult patients diagnosed as Diffuse glioma (WHO grade II-IV) over the p Methods: eriod of January 2015 to January 2020 were included in the study. Immunohistochemical analysis of IDH1R132H, p53 and ATRX was performed. Various demographic, histological and molecular variables were correlated with clinical outcome and assessed for significant impact, if any. Forty-eight cases of Results: Diffuse glioma included in the current study had mean age of 42.2 years with majority of the tumours being Glioblastoma, WHO grade IV (n=30). Overall, IDH1R132H, p53 expression and ATRX loss was observed in 83.3%, 70.8% and 25% cases, respectively. Age at diagnosis (pvalue=0.001), WHO histological grades (p-value=0.038), ATRX loss (p-value=0.025) and IDH1 expression with ATRX loss (p-value=0.036) had significantly better clinical outcome in adult diffuse glioma cases. IDH and ATRX mutations are commo Conclusion: nly seen in diffuse gliomas and are important prognostic markers. It is feasible to detect these mutations by IHC and incorporation of these results in routine histopathology report will help in better prognostication of the patients.