Transient Effectiveness of an Oral 5-Fluorouracil Derivative, S-1, for Epirubicin, Cyclophosphamide and Paclitaxel Refractory Skin Metastases from Possible Occult Breast Cancer in a Male

a Dermatology, b Medical Oncology, c Pathology, and d Surgery, Abstract Recent chemotherapies for skin metastases from breast cancer have shown to be effective for regression, disappearance, and favorable quality of life. We describe the case of a 76-year-old male showing transient effectiveness with an oral 5-fluorouracil derivative, S-1 (tegafur, 5-chloro-2,4-dihydroxypyridine and potassium oxonate), for epirubicin, cyclophosphamide and paclitaxel refractory skin metastases from possible occult breast cancer. The male patient was initially diagnosed as having lymph node metastases in the left axilla as possible occult breast cancer. The skin metastases developed after chemotherapy with a combination of epirubicin and cyclophosphamide, subsequent chemotherapy with paclitaxel, and radiotherapy. Chemotherapy with paclitaxel was resumed for skin metastases, but it was not effective. Alternative chemotherapy with the oral agent S-1 was administered. The skin metastases completely disappeared after the second course, but recurred at the end of the third course. This case suggests that S-1 may be a candidate for chemotherapy for skin metastases from occult breast cancer in males.