[A case with parotid carcinoma showing a pathologically complete response after treatment with S-1 alone].

We report a 57-year-old male case of adenocarcinoma of the parotid gland with metastases to the cervical lymph nodes (T3N2bM0, Stage IV A). S-1 was administered at the conventional dose of 120mg/day for 4 weeks followed by a 2-week rest. After 4 courses of S-1, PET findings showed a remarkable regression of the tumor resulting in a partial response (PR) for the primary lesion. After this treatment, partial parotidectomy and upper neck dissection were performed. The histological effect was Grade 3.