Optimum duration of oral adjuvant chemotherapy of HCFU for colorectal cancer; review of 5-year follow-up.

PURPOSE: To investigate the optimal duration of oral HCFU administration for minimization of side effects induced by long-term administration. PATIENTS AND METHODS: In total, 155 patients allocated to two groups of different duration of the therapy were reviewed: twice or three times per day doses of oral HCFU (8 mg/Kg body weight/day) for 3 months vs. 12 months. RESULTS: Though statistically significant difference was not found in cumulative survival and disease-free rates between the groups due to so many violations of duration of therapy, when reanalyzing the variables in order of real duration of therapy, those rates were significantly higher in patients treated for 300 and more days than less than 300 days (g-Wilcoxon test: p < 0.04). No significant difference was observed in the background factors between the groups. CONCLUSION: At least 300 days is suggested to be necessary to obtain the optimal effectiveness of adjuvant chemotherapy for curatively resected colorectal cancer.