The use of cyclophosphamide, methotrexate, and 5-fluorouracil in the treatment of Merkel cell carcinoma.

Five patients with advanced Merkel cell carcinoma (MCC) are described. Four patients with regional lymph node involvement and one with disseminated skin metastases were treated with systemic chemotherapy, including cyclophosphamide, methotrexate, and 5-fluorouracil (CMF). The patients received a median of six cycles of CMF (range: 2 to 6), and chemotherapy was well tolerated. Four complete and one partial response were noted. Three patients are alive and are disease-free at 5, 12, and 37 months from the onset of CMF chemotherapy. Two patients died from disseminated metastatic disease at 3 and 24 months from the onset of chemotherapy. CMF chemotherapy appears to be an active regimen in the treatment of locally advanced MCC. Further experience with this combination is warranted.