Methyl-CCNU, 6-thioguanine, and 5-fluorouracil in advanced colorectal cancer.

Consecutive studies were undertaken in advanced colorectal adenocarcinoma, comparing two different schedules of the combination methyl-CCNU, 6-thioguanine, and 5-fluorouracil in 89 patients. The two schedules exhibited similar efficacies, with a combined complete and partial remission rate of 17%, a median response duration of 36+ weeks, and a median survival of 53+ weeks. Significant symptomatic benefit was seen in 52% of patients. Toxicity was predominantly hemopoietic and gastrointestinal, being acceptable overall, with only minor qualitative differences between the two protocols. These triple-drug regimens exhibit response rates and survival patterns comparable with those reported for other multidrug combinations and some single agents. It would appear that major improvements in the management of advanced-stage disease must await the availability of more efficacious agents used alone or in combination.