An advanced case of squamous cell carcinoma in the left buccal mucosa, upper gingiva, and maxillary sinus (T4N0M0) showing a complete response to chemotherapy with TS-1

We report a case of advanced squamous cell carcinoma in the left buccal mucosa, upper gingiva, and maxillary sinus (T4N0M0) showing a complete response to oral chemotherapy with TS-1. The patient was an 89-year-old female with severe dementia. We carried out chemotherapy with TS-1 50 mg/day, without surgical treatment. The tumor disappeared clinically at 4 months after 3 courses of the TS-1 administration. Adverse drug reactions, including vomiting, leukopenia and thrombopenia, forced a stop of the administration of TS-1. Although she finally died of in senescence 2 months from the cease of administration, there was no recurrence of the cancer at the time.