Tumor-infiltrating lymphocytes in oral cavity squamous cell carcinoma and its association with clinicopathological parameters

Background: Oral squamous cell carcinoma is one of the most common cancers of the head and neck region. Tumor-infiltrating lymphocytes are naturally occurring mononuclear cells that infiltrate the tumor microenvironment. The aim of the present study is the evaluation of stromal tumor-infiltrating lymphocytes (TILs) in oral squamous cell carcinoma and its association with clinicopathological parameters like age, gender, site, tumor stage, nodal status, grade, lymphovascular and perineural invasion.Materials: A total of 51 patients of oral cavity squamous cell carcinomas who underwent resection were included in the study. Assessment of the stromal TILs was done on sections stained with Hematoxylin and eosin using the scoring criteria proposed by the International Immuno-Oncology Biomarker Working Group. TILs were assessed in percentages as continuous scores and subsequently categorized into low TILs (<20%) and high TILs (>= 20%). The association between TILs and clinicopathological parameters was evaluated using the Fischer exact/Chisquare test.Results: Among the 51 cases evaluated in the present study, low and high TILs were found in 25.5% and 74.5% of cases respectively. TILs were found to show a significant association with tumor size and lymphovascular invasion. However, no significant association was found with age, gender, nodal status, grade, perineural invasion, and site in the oral cavity.Conclusion: The evaluation of TILs as proposed by the International Immuno-Oncology Biomarker Working Group is a simple, inexpensive test. Morphological evaluation of TIL can provide valuable prognostic information in oral cavity squamous cell carcinoma cases and can be incorporated as a part of routine histopathological reporting.