1. Introduction
In March 2017, nivolumab, an immune checkpoint inhibitor, was approved for use in the treatment of squamous cell carcinomas of the head and neck with recurrence or metastasis in Japan. Nivolumab differs from conventional chemotherapeutic drugs, in that, it is known to show a reaction and has been reported to be highly effective for lung cancer, when given after immunotherapy; however, few reports of its use for head and neck cancer treatment are available. Here, we present our experience with a patient who had recurrent cervical lymph node metastasis caused by tongue cancer. Administration of cetuximab and nivolumab led to increased metastasis, but readministration of cetuximab resulted in a remarkable response.