IDH-1, ATRX AND 1P19Q CO-DELETION IN DIFFUSE GLIOMAS

Objective: To stratify diffuse gliomas into subtypes including diffuse astrocytomas, oligodendrogliomas and glioblastomas based on recent molecular updates and assess their frequencies in our local subpopulation. Study Design: Cross-sectional study. Place and Duration of Study: Department of Histopathology, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan, from Jun 2015 to Jul 2017 Methodology: Two hundred and fourteen (n=214) cases of adult diffuse gliomas were evaluated. Clinical and morphological features like age, gender and type of tumor were quantified. Molecular studies including IDH 1 by antibody and PCR, ATRX by antibody and 1p/19q co-deletion by FISH were tested. Gliomas were subcategorised based on WHO 2016 guidelines. Results: Mean age of presentation was 39 years. Overall n=146/214 (68.2%) of the cases were completely classifiable including Diffuse Astrocytomas, Oligodendrogliomas and Glioblastomas. Out of the glioblastomas (n=81), 67/81(n=82.7%) were IDH Wild type and 14/81 (17.3%) were IDH Mutant. Conclusion: In this study, glioblastomas are the most frequent gliomas as categorized by current WHO molecular guidelines followed by diffuse astrocytomas. Oligodendrogliomas are the least common.