Evaluating the IDH, ATRX and P53 Immunohistochemistry in Glial Tumours: A Tertiary Centre Experience

Background: Adult glial tumours continue to be a challenge for medicine for its poor prognostic effects. Due to its invasiveness and resistance to therapy it causes a lot of mortality and morbidity. The recent 5th edition WHO has changed the understanding of the spectrum of glial tumours through cytogenetic advancement. The diagnostic approach to spectrum of glial tumours has been changed due to the inclusion of molecular genetics. Molecular alterations are now the most important factor for diagnosis, classification and prognosis. Aims & Objectives: In the present study we aim to study spectrum of adult glial tumours along with immunohistochemical (IHC) study with IDH1, ATRX and p53 in a tertiary care centre. In this study we compared the histopathological features of these tumours with IHC expression to ascertain any existing correlation between two. This study also looks into any existing relation between the IHC expression and biology of the tumour. Material & Methods: This prospective study was done on 42 patients over a period of one and a half year. Patients with clinical symptoms of brain tumour were selected. The necessary neurosurgical procedure was done followed by histopathological diagnosis of the resected specimen. IHC study with IDH1, ATRX and p53 was done on the glial tumour tissue. All the data including clinic-radiological features were collected and statistical analysis was done using software.Results: Among 42 cases 66.67% of male and 33.33% female. Majority of the cases were glioblastoma. Most of the patients were affected in 4th decade of life. IDH1 expression was inversely related with WHO grade (p=.056) indicating that with increasing grade preponderance of IDH wild type increase and IDH1 mutant decreased. Significant correlation was found between histopathological subtype and IDH1 expression (p=0.000). ATRX expression showed no significant correlation with WHO grade (0.373) and with histopathological subtype. p53 expression also showed no correlation with WHO grade and histopathological subtype.Conclusion: This study was an institution-based study on 42 adult glial tumours. It was carried out during one-and-a-half-year period of January of 2021 to July of 2022. This study has showed that immunohistochemistry (IHC) could be used as a partial surrogate to genetic analysis in low resource setting. However, for more extensive analysis genetic testing is essential. IDH1 IHC in this study corroborated well with histological grade of adult gliomas.