Preliminary study of the optimal dosing schedule for oral UFT/leucovorin chemotherapy.

Background: We evaluated the optimal dosage schedule for combined oral chemotherapy using uracil/tegafur (UFT) and leucovorin (LV) in Yoshida sarcoma-bearing rats. Materials and Methods: The antitumor activity and survival effect were compared between two schedules, thrice daily administration on 5 days of the week followed by 2 drug-free days (schedule A) and twice daily on 7 days of the week (schedule B). Results: Significant tumor growth inhibition and improved survival rate were seen with both schedules of the UFT/LV group as compared to their respective control groups. Tumor growth inhibition was significantly greater in schedule A than schedule B. The number of survivors on day 60 after the tumor inoculation was higher in schedule A although the survival rate did not differ significantly. Conclusion: Administration of UFT/LV for 5 days of the week seemed to exhibit superior antitumor activity, with no increase in the incidence of adverse effects, as compared with the consecutive daily dosing schedule.