Ifosfamide, methotrexate, and 5-fluorouracil: effective combination in resistant breast cancer

Ifosfamide has definite efficacy in many malignant tumours, including breast cancer. In the present study we substituted cyclophosphamide with ifosfamide in the combination CMF (cyclophosphamide, methotrexate, and 5-fluorouracil) regimen in 25 patients with breast cancer whose disease was refractory to CMF or who had relapsed after previous response. Ifosfamide was given in an i.v. infusion at a dose of 1.2 g/m2 daily for 5 days, together with mesna as a uroprotector (at 20% of the ifosfamide dose). Methotrexate was given at a dose of 40 mg/m2 and 5-fluorouracil was given at 600 mg/m2, both by i.v. push. Courses were repeated every 21 days. The 24 evaluable patients received 3-12 courses (average, 5 courses); results included a complete remission in 3 patients (12.5%) and a partial remission in 3 (12.5%). Among the remaining patients, improvement was seen in 4 (16.6%); stable disease, in 7; and progressive disease, in 7 (29.2%). The complete responses lasted for 11+, 13+, and 15+ months, and partial remissions, for 2, 6, and 9 months. The responses were detected in soft-tissue as well as visceral lesions, but not in bony lesions. The responders remain under follow-up. This study shows the efficacy of ifosfamide-containing chemotherapy in breast cancer. As toxicities were tolerable, higher doses of ifosfamide could safely be used in these patients. Use of this combination as first-line therapy in breast cancer could be considered for a future study.