Systemic Therapy in Recurrent or Metastatic Squamous Cell Head and Neck Cancer

Squamous cell head and neck cancer (SCHNC) is the seventh most common cancer worldwide. Most of SCHNC are locally advanced at diagnosis and are treated with combination of surgery and/or radiotherapy with chemotherapy. In spite of aggressive treatment, many patients relapse within the 3 years following the diagnosis. Those whose tumor cannot be resected or reirradiated are treated with a systemic treatment mostly in a palliative setting. They are identified as recurrent and/or metastatic SCHNC (R/MSCHNC) patients. First-line treatment of R/M-SCHNC historically consisted of cytotoxic agents such as methotrexate, bleomycin, or platinum-based protocols until targeted biological therapies were introduced in the 2000's. The recent years witnessed a shift in systemic treatment toward the use of monoclonal antibodies and tyrosine kinase inhibitors, largely based on recent understanding of the role of immune dysfunction in SCHNC. Our review focuses on recent developments of molecular-targeted and immunotherapies in the treatment SCHNC, mostly focusing on R/M-SCHNC. It also highlights ongoing trials and discusses some promising novel targets in HNC, as well as clinical trial design challenges.