Association of PD-L1 immunoexpression with the clinicopathological characteristics and its prognostic significance in OPMD and OSCC: A cross-sectional study

Abstract

Background: Head and neck cancers stands on eighth most prevalent tumor in Oral and Maxillofacial region among which the most frequent malignant tumor is Oral Squamous Cell Carcinoma (OSCC). Worldwide 880,000 patients suffer with head and neck cancer each year, and around 440,000 die due to it. Every day the number of clinical trials is increasing and many research focuses on improved surgery, radiotherapy and also chemotherapy. The immune system, under normal conditions, functions for the protection of the host against various infectious diseases and tumours. Cell surface proteins known as "programmed cell death 1" (PD-1) and "programmed cell death ligand 1" (PD-L1) are essential for the proper functioning of immunological checkpoints. The expression of “PD-L1” positive cells has a direct correlation with poorer prognostic outcome and its correlation is inversed with CD8+T cells infiltrating tumor. This study focuses on association of “PD-L1" immunoexpression to clinicopathological characteristics and its prognostic importance in Oral Premalignant Disorder (OPMD) and OSCC. Methods: The study included surgical tissue samples from individuals who underwent surgery for OSCC. Cases altogether, including OPMD and OSCC were chosen. Examination of sections stained with “PD-L1” antibody was done under Leica DMLB2 (Leica microscope). Results: The present study showed significant correlation between PD-L1 immunoexpression with the clinicopathological characteristics of OPMD and OSCC cases. Conclusions: The premalignant lesions show the intermediate “PD-L1” expression which lie between the normal or hyperplastic lesions to the OSCC. This shows a condition where there are biological adaptations has been confirmed already which directed towards malignant transformation. So, there is a crucial role of “PD-L1’ in the progression of tumor.