Programmed Death Ligand-1 Expression in Gliomas: A Study of Histopathological and Molecular Associations

Abstract

Background: Gliomas are aggressive tumors with limited treatment options. Immunotherapy targets are under evaluation as new therapeutic targets in gliomas. Aims and Objectives: The aims of the study were to analyze expression of PDL1 in adult diffuse gliomas in World Health Organization grade II, III, and IV and to corelate its expression with demographic features, IDH-1, ATRX, and p-53 mutation status. Materials and Methods: This was a case series that included 30 cases of adult diffuse glioma. In all cases, a composite diagnosis including histologic type, grade, and molecular alterations was rendered. PDL1 testing was done by immunohistochemistry using PDL1 SP-263 antibody. Results: PDL1 expression was identified in 33.3% cases in tumor cells and in 6.67% cases in immune cells. All neoplasms with PDL1 expression were astrocytic tumors. PDL1 expression was significantly associated with IDH-1 immunonegative gliomas (P = 0.013). Conclusion: PDL1 is a novel therapeutic target in gliomas. The current study is an attempt to evaluate the expression of PDL1 over the varied spectrum of gliomas. Key Words: