A clinicopathological study on IDH (Isocitrate Dehyrogenase Glioblastoma) wild type gliomas.

Abstract

Objective: To describe the clinicopathological profile of IDH-wildtype gliomas and evaluate their association with age and sex. Study Design: Descriptive Cross-sectional study. Setting: Department of Histopathology, Shaukat Khanum Memorial Hospital and Research Centre, Lahore. Period: December 16, 2023 till June 16, 2024. Methods: A total of 73 IDH-wildtype glioma patients were included. The IDH1 (R132H) immunohistochemistry was performed to identify cases, and was confirmed by molecular testing when clinically indicated. Data from clinical, radiologic, histopathological, molecular, and treatment records were obtained from the hospital records. The diagnosis of the tumors was made by histological diagnosis and based on the 2007 WHO Classification of Central Nervous System Tumors. Data was analysed with SPSS version 26. The clinicopathological features were compared among the age groups and sex by Chi-square test or Fisher's exact test, p-value of <0.05 was regarded as significant. Results: The mean age was 39.45 ± 12.45 years, and 67.1% of patients were male. The most common location of the tumor was the right frontal lobe (37.0%). The most common histological subtype identified was glioma not otherwise specified (52.1%) and 58.9% of the tumors were WHO Grade III or IV. The most common radiological impression was high-grade glioma (47.9%) while surgery combined with chemoradiotherapy was the most common treatment (60.3%). There was a significant association between WHO grade (p<0.001) and radiological impression (p=0.002) and age, in that older patients had higher proportion of Grade IV tumors and high-grade radiological features. No differences were found between age and tumor location, histological subtype, tumor size or treatment modality. Likewise, there were no significant differences between gender with respect to clinicopathological parameters. Conclusion: IDH-wildtype gliomas were primarily in middle-aged men, and often were high-grade tumors of the frontal lobe. Tumour aggressiveness was significantly correlated with increasing age, but not significant for sex. The results help to define the clinicopathological spectrum of IDH-wildtype gliomas and can help to refine the process of diagnostic stratification as well as future prognosis research.