Chemotherapy and immunotherapy for recurrent and metastatic head and neck cancer: a systematic review.

Head and neck cancer (HNC) is a fatal malignancy with an overall long-term survival of about 50% for all stages. The diagnosis is not rarely delayed, and the majority of patients present with loco-regionally advanced disease. The rate of second primary tumors after a diagnosis of HNC is about 3-7% per year, the highest rate among solid tumors. Currently, a single-modality or a combination of surgery, radiotherapy and chemotherapy (CHT), is the standard treatment for stage III-IV HNC. For the recurrent/metastatic setting, in the last 40 years great efforts have been made in order to develop a more effective CHT regimen, from the use of methotrexate alone, to the combination of cisplatin (CDDP) and 5-fluorouracile (5FU) or paclitaxel. Recently, the introduction of cetuximab, an anti-EGFR monoclonal antibody, to the CDDP-5FU doublet (EXTREME regimen) has improved the overall response rate, the progression-free survival and the overall survival (OS) compared to CHT alone. Nowadays, the EXTREME regimen is the standard of care for the first-line treatment of recurrent/metastatic head and neck carcinoma (RMHNC). In the last years, new promising therapies for RMHNC such as immune checkpoint inhibitors (ICIs), which have demonstrated favorable results in second-line clinical trials, gained special interest. Nivolumab and pembrolizumab are the first two ICIs able to prolong OS in the second-, later-line and platinum-refractory setting, with tolerable toxicities. This review summarizes the current state of the art in RMHNC treatment options.