Immunotherapy in Patients with Recurrent and Metastatic Squamous Cell Carcinoma of the Head and Neck

Background: Head and neck squamous cell carcinoma (HNSCC) is the most common malignant cancer occurring in the head and neck area, approximately 90% of the cases. Even in the cases of primary radical treatment (surgical, concomitant chemoradiotherapy or radiotherapy alone), subsequent local recurrence or distant metastases are often observed. in patients with recurrent disease who are unable to receive radical treatment, the results of palliative chemotherapy are not satisfactory. In this review, we summarized the standard treatment options, current development of new drugs and future perspectives in the treatment of patients with recurrent locally advanced and/or metastatic HNSCC. Methods: PubMed databases with words 'head and neck cancer treatment', 'immunotherapy in head and neck cancer treatment' were searched and yielded 186512 and 2249 papers respectively. We selected the most cited articles and reports presenting new immunotherapy agents and drug combinations in HNSCC. Results: Recently, two new agents been approved in the treatment of recurrent locally advanced and/or metastatic HNSCC. These are immune-checkpoint inhibitors targeting PD1 (nivolumab and pembrolizumab) which are the most active drugs in the second line treatment of advanced HNSCC. Still, the first line 'golden standard' is the chemotherapy regimen (cisplatin, 5-fluorouracyl) combined with cetuximab. Many phase 3 studies are currently ongoing, evaluating the efficacy of combinational treatment-anti-CTLA4 with anti-PD1 or anti-PD-L1. Very encouraging results have been shown in early phase studies evaluating the combination of immune-checkpoint inhibitors with tumor microenvironment immunosuppressive inhibitors. Conclusion: Despite the huge progress in the systemic treatment of patients with recurrent locally advanced and/or metastatic HNSCC, the disease at this stage remains incurable. Undoubtedly, further research in the field of biomarkers for effective immunotherapy is needed in order to select a group of patients whose will benefit from this therapy, as the treatment is still ineffective in most patients.