Abstract
We report a case of lower gingival squamous cell carcinoma of the right mandible, which completely responded to multidisciplinary therapy including nivolumab. The patient was an 86-year-old man. An elastic-hard mass （measuring 90×30mm） in the right mandible with pain and paresthesia of the lower lip were observed at the initial visit. The lesion was histopathologically diagnosed as squamous cell carcinoma by a biopsy, and he was treated with the combination therapy of cetuximab （Cmab） and paclitaxel （PTX） as chemotherapy. The size of the tumor was reduced by the chemotherapy, but we unwillingly applied Cmab therapy because the patient refused salvage surgery. Unfortunately, it was ineffective, and the second combination therapy of Cmab and PTX was unsuccessfully performed. Thereafter, palliative radiotherapy with 30Gy followed by nivolumab therapy was applied. However, interstitial changes in a part of the lung field were observed after performing nivolumab therapy three times, and we decided to discontinue the nivolumab therapy because of the high risk of developing interstitial pneumonia. Surprisingly, however, the mandibular tumor completely responded 4 months later. There has been no evidence of recurrence for 1 year and 8 months after showing complete response.
