Chemotherapy of advanced colorectal cancer. A randomized trial of sequential methotrexate and 5-fluorouracil.

Fifty-five patients with advanced colorectal cancer were entered into a randomized controlled clinical trial to evaluate order of administration and sequential methotrexate (MTX) and 5-fluorouracil (5-FU) therapy. Patients were randomized to receive either MTX, 250 mg/m2, followed 1 h later by 5-FU, 600 mg/m2, or 5-FU followed 1 h later by MTX in the same doses. Fifty-four patients were evaluable for response, of whom 15 (28%) achieved objective partial tumor response. There were no significant differences between the two sequences in response rate, time to treatment failure, or survival duration. The results of this study do not indicate a clinically significant difference between the two sequences tested, in which MTX preceded or followed 5-FU by 1 h. Determination of the value of these drugs given sequentially at longer intervals must await appropriate controlled trials.