Sixteen patients with advanced gastrointestinal cancer (colorectal 12/16, gastric 4/16) were treated with a combination of 5-fluorouracil (5-FU) plus 1-(2-chlorethyl)-3(4-methyl-cycloexyl)-1-nitrosourea (Me-CCNU). The therapeutic program consisted of orally administered Me-CCNU (140 mg/m2) and intravenous 5-FU (9.5 mg/kg by bolus injection for 5 days). The cycles were repeated at 6-week intervals. At the beginning of the therapy, 11/16 patients were in performance status (PS) 0-1 and 5 patients in PS 2-3. Eight patients developed early progressive disease between the 1st and 2nd course of therapy. Only a minor tumor response was observed in the remaining 50% of the patients. However, the patients with stabilized disease lived longer (11.8 months) than non-responders (3.5 months).