Induction Therapy with S-1 for Spindle Cell Carcinoma of the External Auditory Canal

Abstract

We report an unusual case of spindle cell carcinoma of the external auditory canal, which responded well to two weeks’ treatment with the oral fluoropyrimidine anticancer drug S-1 (80 mg/body/day) followed by surgical resection. After the S-1 treatment, the tumor was significantly reduced in size, and a pathological examination only detected small lesions composed of malignant cells. We then conducted a lateral temporal bone resection combined with left modified neck dissection. The patient did not demonstrate any evidence of local recurrence or distant metastasis during the 5-year follow-up period. It is suggested that S-1 played an important role in reducing the size of the tumor to allow radical resection of the tumor with a sufficient surgical margin in the present case and that induction chemotherapy with S-1 prior to surgery might be an effective treatment strategy for controlling spindle cell carcinoma of the ear.