A phase II study of sequential methotrexate and 5-fluorouracil in colorectal carcinoma.

Nineteen patients with locally recurrent or metastatic colorectal carcinomas were treated with 3-weekly cycles of methotrexate (MTX) given as a loading dose of 100 mg m-2 and a subsequent 12 h infusion of 400 mg m-2, followed by 5-fluorouracil (5-FU) 900 mg m-2 as a bolus injection on completion of infusion. No objective responses were seen in 14 evaluable patients. One early death was treatment related, and four patients were withdrawn from the study after a single course as toxicity was considered unacceptable. The results suggest that in this regimen of sequential MTX and 5-FU, any synergism may be restricted to drug toxicity as no therapeutic benefit was evident.