Feasibility of 5-days-on/2-days-off UFT/leucovorin in post-operative long-term adjuvant chemotherapy for colorectal cancer

Previous clinical studies have shown that the oral uracil/tegafur (UFT)/leucovorin (LV) regimen, in which the drugs are taken for 28 consecutive days every 35 days, is equivalent to an infusional 5-fluorouracil (5-FU)/LV regimen for the treatment of colorectal cancer. A 5-days-on/2-days-off schedule for UFT/LV has been proposed as the same schedule for UFT has been reported to be safe and have good compliance. However, few studies have been performed with regards to the feasibility of the UFT/LV regimen. The results of the 5-days-on/2-days-off schedule were compared with those of the consecutive schedule in adjuvant chemotherapy. Twenty-eight patients were treated with the 5-days-on/ 2-days-off schedule of UFT (300 mg/m2/day)/LV (75 mg/body/day), and another 12 patients were treated with the consecutive schedule. In the 5-days-on/2-days-off schedule, 24 of 28 patients (86%) received all the scheduled doses. In the consecutive schedule, 10 of 12 patients (83%) received all the scheduled doses. The mean relative dose intensities for the 5-days-on/2-days-off and consecutive schedules were 0.92 and 0.87, respectively. The toxicities were milder in the 5-days-on/2-days-off schedule compared with the consecutive schedule. The disease-free survival in patients with the 5-days-on/2-days-off schedule tended (P=0.13) to be longer compared with the consecutive schedule. The results of the present study indicate that the 5-days-on/2-days-off schedule of UFT/LV may be feasible and cause no severe toxicities in long-term adjuvant chemotherapy.