Phase III study comparing a semimonthly with a monthly regimen of fluorouracil and leucovorin as adjuvant treatment for stage II and III colon cancer patients: final results of GERCOR C96.1.

PURPOSE: This randomized, 2 x 2 factorial study compared a semimonthly regimen (fluorouracil [FU] and leucovorin [LV] semi-monthly is LV5FU2) with a monthly regimen of FU and LV (mFU/LV) as well as 24 weeks versus 36 weeks of each regimen as adjuvant treatment of stage II and III colon cancer.

PATIENTS AND METHODS: LV5FU2 was administered semimonthly for 2 days as racemate (dl) or levogyre (l-; 200 or 100 mg/m(2)) as a 2-hour infusion, followed by 400 mg/m(2) FU bolus and a 600-mg/m(2) FU 22-hour continuous infusion. FU and LV were administered monthly (mFU/LV) for 5 days as dl- or l-LV 15-minute infusion, followed by a 400 mg/m(2) FU 15-minute infusion. The primary end point was disease-free survival (DFS).

RESULTS: Between September 1996 and November 1999, 905 patients with stage II (43%) and III (57%) colon cancer were enrolled. The median follow-up was 6 years. There was no statistically significant difference between mFU/LV and LV5FU2 in terms of DFS (150 v 148 events; hazard ratio [HR],1.01; 95% CI, 0.806 to 1.269; P = .94) and overall survival (OS; 104 v 103 events; HR,1.02; 95% CI, 0.77 to 1.34; P = .91). No statistical difference was observed between 24 or 36 weeks of chemotherapy. Median survival from metastatic relapse was 24 months. The survival of patients with metastatic relapse (n = 243) was significantly longer for patients with a longer time from random assignment to relapse (< 1, 1 to 2, >or= 2 years; log-rank test for trend P, .0497).

CONCLUSION: DFS and OS were not statistically different between treatment groups and treatment durations. These data confirm the value of LV5FU2 as control arm in the Multicenter International Study of Oxaliplatin/5FU-LV in the Adjuvant Treatment of Colon Cancer and Pan-European Trials in Adjuvant Colon Cancer studies.