Inhibitory Effect of the Oral 5-Fluorouracil (5-FU) and Sustained Release type 5-FU Administration on Hepatic Dissemination of Colorectal Cancer Cells

Objectives: To exmine the preventive effects of Conventional 5-FU and sustained release type 5-FU ad-ministration on the hepatic dissemination of colorectal cancer cells during surgical maneuver in the animal model. Materials and methods: In this experiment, rabbits were used as an animal hepatic metastasis model utilizing the injection of VX2 carcinoma cells into the portal vein. Two forms of 5-FU, i.e. conventional 5-FU and sustained-release 5-FU, were orally administered with 3 different shedules. Three schedules of 5-FU oral administration were attempted as follows: 1) 10 mg/kg preoperative dosage only, 2) preoperative 10 mg/kg plus postoperative dosage at 6 mg/kg/day for 6 days, and 3) postoperative dosage at 6 mg/kg/day for 7 days. Te hepatic metastases were compared by volume among the 6 groups mentioned above and controls. Results and Conclusion: Statistical analysis revealed that preoperative administration of 5-FU significantly reduced the hepatic metastasis while postoperative administration of 5-FU did not influence the results. Compared to the efficacy of conventional 5-FU, sustained-release 5-FU tended to more effectively suppress hepatic metasta- ses.