Tumor Infiltrating Lymphocytes as Immunebiomarkers in Oral Cancer: An Update

The high morbidity and mortality associated with oral cancer has necessitated the exploration of newer diagnostic and prognostic biomarkers. In recent decades, targeting immune landscape has emerged as a newer approach as aggressive tumor biology and therapy resistance are influenced by the interplay between tumor and immune cells. A reciprocal association between chronic inflammation and carcinogenesis is well established and tumor infiltrating lymphocytes (TILs) represent inflammatory milieu of tumor microenvironment (TME). The varied T-cell phenotypes in different stages of cancer influence the prognostic and predictive response of the patients. Along with the conventional treatment options, Immunotherapy has evolved as a suitable alterative for oral carcinoma patients especially with recurrent and metastatic disease (R/M) but response is still unpredictable. Tumor microenvironment (TME) plays a key role to either lessen or boost up immune responses. There is an urgent need for extensive studies to be undertaken to better understand how tumor cells escape immune surveillance and resist immune attack. This review is an attempt to elucidate the concept of immune infiltrate in oral squamous cell carcinoma (OSCC) and thus, understanding the role of immunoscore as an adjunct to TNM staging to guide patient treatment.