Controlled trial of fluorouracil and low-dose leucovorin given for 6 months as postoperative adjuvant therapy for colon cancer.

Abstract

The goal of this study was to determine the efficacy of intensive-course fluorouracil (5FU) plus low-dose leucovorin given for 6 months following potentially curative resection of colon cancer. Three hundred seventeen patients with high-risk stage II or stage III colon cancer were randomly assigned 3 to 4 weeks following surgery to receive either (1) chemotherapy with six cycles of 5FU (425 mg/m2) plus leucovorin (20 mg/m2) by rapid intravenous injection daily for 5 consecutive days every 4 to 5 weeks, or (2) observation. The median follow-up duration is 72 months for patients still alive. Patients who received postoperative 5FU plus leucovorin experienced significant improvement in time to relapse (P < .01) and survival (P = .02) compared with control patients treated with surgery alone. Stomatitis, diarrhea, and leukopenia were the predominant chemotherapy toxicities. There were no treatment-related deaths. These results indicate that intensive-course 5FU plus low-dose leucovorin is effective in preventing tumor relapse and improving survival in patients with high-risk colon cancer. These benefits were seen with only six cycles of treatment, using low-dose leucovorin in combination with 5FU on a schedule convenient for outpatient administration.