Immuno-oncology in head and neck squamous cell carcinoma - a narrative review

Immuno-oncology studies the immune system in cancer. In recent decades, immunotherapy has shown a good response to the treatment of various locally advanced and metastatic cancers. The main mechanisms of action include stimulation of the patient's own immune system to enhance immune responses acting in tumor escape pathways. This review examined the literature related to immune system mechanisms in head and neck squamous cell carcinoma (HNSCC) and their application in immunotherapy using biomarkers. The PUBMED, LILACS, MEDLINE, WHOLIS, and SCIELO databases were searched using the terms squamous cell carcinoma, head and neck, immuno-oncology, immunotherapy, and immunology. The main drugs currently available for clinical use in patients diagnosed with HNSCC include pembrolizumab and nivolumab, both classified as check-point inhibitors. These immunobiological agents improve patient survival and quality of life. Many authors and clinical trials point out that the recommendation of these agents is linked to the dose of PD-L1 (ligand expressed primarily by tumor cells), which proved to be an unreliable biomarker in the patient selection. Recommendation of immunotherapy depends on reliable biomarkers that must be identified in order to achieve good therapeutic results.