BIOCHEMICAL MODULATION OF 5-FLUOROURACIL - A RANDOMIZED COMPARISON OF SEQUENTIAL METHOTREXATE, 5-FLUOROURACIL AND LEUCOVORIN VERSUS SEQUENTIAL 5-FLUOROURACIL AND LEUCOVORIN IN PATIENTS WITH ADVANCED SYMPTOMATIC COLORECTAL-CANCER

Background: The optimal chemotherapy for advanced colorectal carcinoma is not known. Two regimens, both based upon biochemical modulation of 5-FU, were compared in a randomized multicenter trial. Patients and methods: A total of 202 symptomatic patients were randomly allocated to receive either sequential methotrexate, 250 mg/m2, during the first 2 hours and 5-FU, 500 mg/m2, at hours 3 and 23 followed by leucovorin rescue initiated at hour 24 (15 mg x 8) (MFL) or sequential 5-FU 500 mg/m2 followed by leucovorin 60 mg/M2 30-40 minutes later, on days 1 and 2 (FLv). Treatments were repeated every 14 days for eight courses and then every 3 to 4 weeks. Four patients were unevaluable. Results: The two treatments were equally effective with respect to objective response rates (complete (CR) + partial (PR), MFL 17%, FLv 21%), subjective response rates (symptom relief in the absence of severe adverse effects, 45% vs. 37%), and survival (median 7.5 vs. 9 months). All responses lasted at least 4 months. Overall, toxicity was low and comparable between the groups, but serious toxicity was more common in the MFL group. Conclusions: Since FLv is easier to administer and carries less risk for serious toxicity, it should be recommended as a first-line treatment before MFL. On either regimen, about 40% of symptomatic patients can expect palliation, i.e., symptomatic relief without severe adverse effects, for at least 4 months.