5-fluorouracil plus leucovorin is an effective adjuvant chemotherapy in curatively resected stage III colon cancer: long-term follow-up results of the adjCCA-01 trial

Background: Adjuvant postoperative treatment with 5-fluorouracil (5-FU) and leucovorin in curatively resected stage III colon cancer significantly reduces the risk of cancer recurrences and improves survival. The impact of 5-FU plus leucovorin on survival and tumor recurrence was analyzed in a long-term follow-up study in comparison with the effects of 5-FU plus levamisole in the prospective multicenter trial adjCCA-01. Patients and methods: Patients with a curatively resected stage III (International Union Against Cancer) colon cancer were stratified according to tumor, node and grading category and randomly assigned to receive one of the two adjuvant treatment schemes: 5-FU 400 mg/m(2) body surface area intravenously in the first chemotherapy course, then 450 mg/m(2) x 5 days, plus leucovorin 100 mg/m(2), 12 cycles (arm A), or 5-FU plus levamisole (Moertel scheme; arm B). Results: Six hundred and eighty (96.9%) of 702 patients enrolled into this study were eligible. To date, 261 patients have died, 117 on arm A and 144 on arm B (P = 0.007). After a median follow-up time of 82 months, the 5-FU plus leucovorin combination significantly improved disease-free survival [79.8 months in arm A versus 69.3 months in arm B (P = 0.012)] and significantly increased median overall survival (88.9 months in arm A versus 78.6 months in arm B; P = 0.003). Adjuvant treatment with 5-FU plus levamisole as well as 5-FU plus leucovorin was generally well tolerated; only a minority of patients experienced grade 3 and 4 toxicities. Conclusions: After curative resection of a stage III colon cancer, adjuvant treatment with 5-FU plus leucovorin is generally well tolerated. This long-term follow-up study demonstrates that adjuvant treatment with 5-FU plus leucovorin given for 12 cycles is significantly more effective than 5-FU plus levamisole (Moertel scheme) in reducing tumor relapse and improving survival.