Cyclophosphamide, methotrexate, and 5-fluorouracil in the treatment of metastatic prostate cancer. A southwest oncology group study

Abstract
Background. Hormone-refractory metastatic prostate cancer remains a therapeutic challenge. Cyclophosphamide, methotrexate, and 5-fluorouracil (CMF), a drug combination that is active in solid tumors, was evaluated using specific response criteria. Methods. Fifty-two eligible patients with measurable (19), evaluable (29), or bone scan only (4) metastatic prostate cancer were treated with cyclophosphamide, 100 mg/m2 every day by mouth, methotrexate, 15 mg/m2 intravenously weekly, and 5-fluorouracil, 300 mg/m2 intravenously weekly. Treatment was given continuously unless interrupted by toxicity or disease progression. Results. There were two partial responses (7%) among the evaluable patients. Six (32%) measurable patients and four (14%) evaluable patients had stable disease. Median time to progression was 3.2 months for measurable and 2.8 months for evaluable disease patients. Median survivals were 10.9 and 10.2 months, respectively. There was no difference between the two groups with regard to response rate or survival. Toxicity was acceptable and consisted primarily of myelosuppression. Conclusions. CMF is minimally active in hormonerefractory metastatic prostate cancer.