Unraveling the Significance of Immune Contexture in Oral Cancer

Abstract

Numerous epidemiological and molecular biological studies have shown that inflammatory cells and cytokines in the tissues that surround tumors contribute to tumor development and progression. The immune response to tumors is complex, involves the interaction of several cell types of the adaptive and the innate immune systems, and has an important role in the progression of a variety of solid tumors. Tumor-infiltrating lymphocytes (TILs) have been studied as an indicator of tumor inflammation, and it has been reported that TIL subsets have their own roles in cancer progression. The differences in T-cell repertoire in different stages of cancer influence the prognostic and predictive response of the patient. Several studies have reported that CD3+ and CD8 + TILs are associated with good clinical prognosis in different cancer types including head-and-neck cancer, although contradictory reports are available regarding the role of CD4+ T-cells and + regulatory T-cells (Treg cells; forkhead box protein 3 [FOXP3] cells). This review is an attempt to elucidate the concept of immune infiltrate in oral squamous cell carcinoma to comprehend the role of immunoscore as an adjunct to tumor, node, metastasis staging to guide patient treatment. Immunoscore could provide an excellent setting for immunotherapeutic strategies to complement current standard chemoradiation and may benefit high-risk patients. We emphasize the need to standardize methodology, scoring criterias and also to develop validated cutoff values. Tumor aggressiveness and therapy resistance are influenced by the interplay between tumor cells and their microenvironment, only a better understanding of this will permit a rational design of new immunotherapeutic approaches.