A randomized, double-blind trial of fluorouracil plus placebo versus fluorouracil plus oral leucovorin in patients with metastatic colorectal cancer.

Purpose: A prospectively randomized trial was performed to determine whether the combination of fluorouracil (FU) plus leucovorin (FU-LV) administered orally is more effective than equitoxic FU for patients with metastatic colorectal cancer.

Patients And Methods: A double-blind, placebo-controlled trial design was used to eliminate observer bias. An escalating FU dosing schedule was used to achieve equal toxicity. End points were response, time to treatment failure (TTF), and eight quality-of-life (QL) parameters. A crossover arm allowed FU-treated patients to receive FU-LV combination treatment after treatment failure.

Results: Response rate was 32% for FU-LV versus 23% for FU (P = .15). Median TTF was 22 versus 16 weeks (P = .27). Median survival time was 44 versus 54 weeks (P = .26). QL was the same for both treatments, except for days of hospitalization, which was greater for FU-LV (P < .001). Toxicities were similar to those previously reported for FU-LV and FU alone.

Conclusion: Oral LV-FU produces the same efficacy and toxicity pattern as has been reported for intravenous LV-FU. When FU-LV is compared with equitoxic doses of FU, there is no difference in patient outcome. These results suggest that patients with advanced disease should receive FU at doses adequate to produce toxicity.