Adjuvant chemotherapy with uracil-tegafur (UFT) for stage III colorectal cancer: Final results of randomized trials by the National Surgical Adjuvant Study of Colorectal Cancer (NSAS-CC)

Abstract

4049 Background: In the latter 1990s, no consensus was reached as to whether adjuvant chemotherapy was standard treatment for completely resected stage III colorectal cancer in Japan. At that time, we started two randomized controlled trials to clarify the role of adjuvant chemotherapy of stage III colon and rectal cancer in the same time. Methods: Patients with completely resected stage III cancer of the colon or rectum (PS, 0 to 2; age, 20 to 75 years; no other adjuvant therapy) were eligible for these trials. Patients were registered within 6 weeks after surgery and were randomly assigned to receive surgery alone (control group) or surgery followed by treatment with UFT (400 mg/m2/day), given for 5 consecutive days per week for 1 year (UFT group). The target number of patients was 500 for colon cancer and 400 for rectal cancer (hazard ratio = 0.67, one-sided a= 0.05, β= 0.2). The primary endpoint was relapse-free survival (RFS), and the secondary end point was overall survival (OS). Results: Between October 1996 and April 2001, a total of 334 patients with colon cancer and 276 with rectal cancer were enrolled. Four ineligible patients were excluded; data from the remaining 332 patients with colon cancer and 274 with rectal cancer were analyzed. The patients’ characteristics were similar in the groups. Analysis of the results of follow-up until March 2006, at least 5 years after surgery in all patients (median follow-up period, 6.2 years), showed no significant difference in RFS or OS in colon cancer. In rectal cancer, however, RFS and OS were significantly better in the UFT group than in the control group. The only grade 4 toxicity was diarrhea, occurring in 1 patient with colon cancer and 1 patient with rectal cancer. Conclusions: Postoperative adjuvant chemotherapy with UFT is well tolerated and improved RFS and OS in patients with stage III rectal cancer. In colon cancer, the expected benefits were not obtained (hazard ratio = 0.67). [Table: see text] No significant financial relationships to disclose.