Current Treatment Options for Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

This review highlights the evidence-based data to support current best management practices for patients with recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). Current limitations and areas of emerging therapeutics are also emphasized. The cornerstone of palliation for patients with R/M HNSCC is a platinum-based backbone. Platinum doublets induce higher response rates than single agents but do not demonstrate a survival advantage and are associated with increased toxicity. The only regimen to demonstrate survival superiority is platinum, fluorouracil, and cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor (EGFR). EGFR inhibitors, including monoclonal antibodies and tyrosine kinase inhibitors, have achieved only modest success in R/M HNSCC, illustrating the importance of identifying predictive biomarkers and finding ways to overcome mechanisms of resistance. Although phosphoinositide 3-kinase pathway alterations are present at a high rate in HNSCC, the identification of efficacious agents in patients with activating alterations has yet to be discovered. Immunotherapy represents an attractive treatment strategy for R/M HNSCC, with promising preliminary data from studies involving immune checkpoint blockade and toll-like receptor agonists. Human papillomavirus has a prognostic role in R/M disease; therefore, stratification of patients by human papillomavirus status in clinical trials is indicated. Although under-represented in clinical trials, elderly patients experience similar survival outcomes compared with younger patients, albeit with increased toxicity. Despite therapeutic advances, prognosis nonetheless remains poor for patients with R/M HNSCC. Enrollment of patients onto clinical trials to investigate novel therapeutics and identify predictive biomarkers is necessary to further refine and improve outcomes.