A prospective randomized study was performed for 72 patients with large bowel cancer, and 36 cases each of rectal cancer and colonic cancer, who had received curative resection respectively. The regimen consisted of two adjuvant chemotherapies: group A, postoperative administration of FT-207 suppository; group B; preoperative and postoperative administration of the same suppository. A follow-up study was then done. The results revealed the 5-year survival rate to be 65.1% for group A and 72.4% for group, B respectively. With rectal cancer, 5-year survival was 57.8% for group A and 70.5% for group B respectively. In colonic cancer the figures were 70.8% for group A and 75.0% for group B. Thus, there was no significant difference but a somewhat higher survival rate was observed in the preoperative plus postoperative administration group. Comparison of in the prognosis two groups classified according to the degree of nodal metastasis and invasion revealed good results in group B. The above-mentioned facts suggest that pre- and post-operative administration of FT-207 suppositories as adjuvant chemotherapy for colorectal cancer is superior to postoperative use alone.