[Multicenter comparative study of the recurrence-inhibitory effect of oral fluoropyrimidine drugs in patients with colorectal cancer following curative resection].

HCFU and UFT were reported effective in adjuvant chemotherapy for colorectal cancer. This investigation was planned as a randomized study to compare the usefulness of combination therapies with mitomycin C (MMC)+HCFU and MMC+UFT as postoperative adjuvant chemotherapy in patients with colorectal cancer following curative resection, in terms of survival rate, recurrence rate, and adverse drug reactions. A total of 501 patients consisting of 252 patients with stage III/IV colon cancer (Colorectal Cancer Handling Rules, 4th Ed.) for which macroscopic curative resection was possible and 249 patients with stage II/III/IV rectal cancer (ibid, 4th Ed.) were registered from 40 participating institutions. The patients were randomly allocated to two groups with colon cancer and rectal cancer employed as stratification factors. Beginning on Day 14 after surgery, HCFU at 300 mg/day was administered to one group and UFT at 300 mg/day or 400 mg/day to another group, both orally and daily for one year. MMC 6 mg/m2 was administered intravenously to both groups on the day of surgery and the day following. Among the 501 patients, 496 patients (99%) were eligible. The 5-year survival rates were 77.1% for the MMC+ HCFU group and 79.2% for the MMC+UFT group, with the 5-year recurrence-free survival rates were 76.1% and 72.9%, respectively, neither showing a significant difference between the groups. Adverse drug reactions appeared in 23% of patients in the MMC+HCFU group and in 19% in the MMC+UFT group, with no serious reactions. One year after surgery the administration completion rates were good, at 82% for the MMC+HCFU group and 83% for the MMC+UFT group. No clear difference in effectiveness was noted between MMC+HCFU therapy and MMC+UFT therapy as postoperative adjuvant chemotherapy for colorectal cancer. The administration completion rates were good, and no serious adverse drug reactions were observed for either therapy. It was thus considered that both therapies could be administered safely, and both were useful as postoperative adjuvant chemotherapies for colorectal cancer. It is considered necessary to compare them with standard therapies in Western countries in the future.