Assessment of immune infiltrate in oral cancer: An immunohistochemical study

The biomarkers of antitumour immune response provide valuable prognostic information and aid in the stratification and treatment of cancer. Tumour microenvironment (TME) defines the cancer biology, and assessment of tumour-infiltrating lymphocytes (TILs) in oral squamous cell carcinoma is an arena of vigorous research.

The present study is designed to determine the association of CD8⁺ and CD3⁺ T lymphocytes with clinicopathological parameters and their role as prognostic biomarkers.

This is an observational and institution-based study. Tissue blocks of histologically proven oral squamous cell carcinoma patients were retrieved from archives, and all clinicopathological parameters were noted. The semiquantitative and quantitative methods of TILs assessment were meticulously applied both in the stromal and intratumoural regions using immunohistochemistry. The standard statistical methods were employed for data analysis.

A significant association of CD8⁺ T lymphocytes with clinical tumour size (P = 0.012), clinical (P = 0.011), and pathological (P = 0.048) staging was observed. CD3⁺ T lymphocytes were significantly associated with clinical node involvement. However, no survival benefits were observed with both biomarkers.

CD8⁺ T lymphocytes showed a significant association with clinical tumour size, clinical, and pathological staging. However, the study did not provide evidence for the prognostic value of the presence of CD3⁺ and CD8⁺ T lymphocytes in the tumour epithelium and stroma of oral cancer patients.