Multimodal biochemical modulation of 5-fluorouracil by leucovorin, methotrexate, and interferon alpha in patients with advanced colorectal cancer

A total of 26 patients with advanced colorectal cancer received 60 mg/m(2) methotrexate i.v. on days 1-4; 400 mg/m(2) 5-fluorouracil i.v. on days 2, 3, 5, and 6; and 100 mg/m(2) 6S-leucovorin i.v. on days 2, 3, 5, and 6. Interferon-alpha 2b at a dose of 3 million U was given i.m. daily for the 6 days of chemotherapy. Courses were repeated every 3 weeks. There were four partial responses for a response rate of 15% (95% confidence interval 2-28%). In all, 14 patients expressed grade 3 toxicity; 9 patients had diarrhea, 3 had stomatitis, and 2 developed leukopenia. In conclusion, multimodal biochemical modulation of 5-fluorouracil, at least on this schedule, does not seem to be effective, as it results in severe toxicity.