Phase II trial of combination chemotherapy of colonic cancer with 5-fluorouracil, mitomycin C, and hexamethylmelamine.

HexMF consists of hexamethylmelamine 150 mg/m2 D2-15, mitomycin C (MMC) 10 mg/m2 D2 and 5-fluorouracil (5-FU) 30 mg/kg/day as a continuous infusion D1-5 in 4-5 week cycles. It was designed as an alternative to treating patients with standard single agents in sequence, thereby preventing the testing of new drugs as part of primary therapy. Median survival was 12+ months for patients with measurable and 18+ months for patients with nonmeasurable colorectal cancer. It was 9+ months from the onset of secondary chemotherapy. Toxicity included severe thrombocytopenia (50%), severe leukopenia (25%), and moderate stomatitis (50%). Only one instance of leukopenia was life-threatening. The MMC and 5-FU infusion skeleton provides an attractive strategy for testing new drugs as primary therapy. HexMF itself has a potentially broad antitumor spectrum and excellent acceptance by patients. It is suitable for additional phase II trials.