Caffeine-potentiated chemotherapy for clear cell sarcoma: a report of five cases

Clear cell sarcoma is a rare malignant tumor of soft tissue which is most commonly encountered in the extremities, especially in the foot and ankle. This tumor is slow-growing and looks like a benign tumor; it is therefore often treated inadequately and its high rate of recurrence and metastases results in a poor prognosis. Caffeine has been used as a chemotherapy potentiator that inhibits DNA damage repair and enhances the cytocidal effects of anti-cancer drugs. This study reports the effect of caffeine-potentiated chemotherapy for clear cell sarcoma in five patients. Caffeine-potentiated chemotherapy was administered to five patients with clear cell sarcoma. Three to five courses of intra-arterial chemotherapy using cisplatin, doxorubicin and caffeine were administered preoperatively, at 3-week intervals. Conservatively, wide margin surgery was performed following the preoperative chemotherapy. Intravenous cisplatin and doxorubicin with caffeine were administered three to six times to the patients who responded to the preoperative chemotherapy. This study evaluated the response to chemotherapy, recurrence, metastasis and the overall prognosis in these five patients. Four of the eligible patients responded to preoperative chemotherapy. Local recurrence occurred in only one of the five patients. Distant metastasis newly developed in one patient. All five patients survive. Caffeine-potentiated chemotherapy can be effective treatment for clear cell sarcoma not only as initial therapy, but also as salvage therapy.