Expression Of Pd-1 And Pd-L1 In Head And Neck Squamous Cell Carcinoma And Its Association With Lymphnodal Metastasis

Abstract

Introduction Head and Neck Squamous Cell Carcinoma (HNSCC) is a highly aggressive cancer in which several key biological processes become altered such as mechanisms of cell differentiation, regulation of the cell cycle, epithelial–mesenchymal interactions, programmed cell death, formation of new blood vessels and the ability of tumor cells to invade and metastasize.

Aim & Objectives To assess PD-1 and PD-L1 expression in tumor-infiltrating lymphocytes (TILs) and tumor cells of Head and Neck Squamous Cell Carcinoma (HNSCC) cases and to determine its association with nodal involvement and clinicopathological features.

Methodology This is a cross-sectional study done on 53 diagnosed cases of HNSCC who underwent composite dissection with lymph node resection from January 2022 to September 2024. Immunohistochemical expression of PD-1and PD -L1was done. Tonsil tissue was used as a positive control for both markers. Immunoreactivity score was done using cell staining intensity as score 0 = <1%, score 1 =1-5%, score 2=5-50% and score 3= >50%. Statistical analysis was carried out using the chi-square test, and a p-value ≤0.05 was considered statistically significant.

Results In the present study, 36 patients (67.9%) were male and 17 (32.1%) were female with a mean age of 30 years. The buccal mucosa was the most frequently involved site, accounting for 27 cases (50.9%). Among the 53 patients, 24 (54.7%) exhibited lymph node metastasis, which showed positive expression of both PD-1 and PD-L1 in the primary tumor cells. A statistically significant association was observed between PD-1 and PD-L1 expression in the primary tumor and lymph node metastasis, with p-values of <0.01 and <0.02 respectively.

Conclusion A significant correlation was observed between the immunohistochemical expression of PD-1 and PD-L1 and lymph node metastasis in HNSCC. Evaluation of PD-1 and PD-L1 expression in OSCC offers important prognostic insights and may guide the design of targeted immunotherapies to enhance patient outcomes.