Clinical Trial to Assess the Relative Efficacy of Fluorouracil and Leucovorin, Fluorouracil and Levamisole, and Fluorouracil, Leucovorin, and Levamisole in Patients With Dukes' B and C Carcinoma of the Colon: Results From National Surgical Adjuvant Breast and Bowel Project C-04

Abstract

PURPOSE: To compare the efficacy of leucovorin-modulated fluorouracil (FU+LV) with that of fluorouracil and levamisole (FU+LEV) or with the combination of FU+LV and levamisole (FU+LV+LEV). PATIENTS AND METHODS: Between July 1989 and December 1990, 2,151 patients with Dukes' B (stage II) and Dukes' C (stage III) carcinoma of the colon were entered onto National Surgical Adjuvant Breast and Bowl Project protocol C-04. Patients were randomly assigned to receive FU+LV (weekly regimen), FU + LEV, or the combination of FU+LV+LEV. The average time on study was 86 months. RESULTS: A pairwise comparison between patients treated with FU+LV or FU+LEV disclosed a prolongation in disease-free survival (DFS) in favor of the FU+LV group (65% v 60%; P = .04); there was a small prolongation in overall survival that was of borderline significance (74% v 70%; P = .07). There was no difference in the pairwise comparison between patients who received FU+LV or FU+LV+LEV for either DFS (65% v 64%; P = .67) or overall survival (74% v 73%; P = .99). There was no interaction between Dukes' stage and the effect of treatment. CONCLUSION: In patients with Dukes' B and C carcinoma of the colon, treatment with FU+LV seems to confer a small DFS advantage and a borderline prolongation in overall survival when compared with treatment with FU+LEV. The addition of LEV to FU+LV does not provide any additional benefit over and above that achieved with FU+LV. These findings support the use of adjuvant FU+LV as an acceptable therapeutic standard in patients with Dukes' B and C carcinoma of the colon.