Protracted treatment with tegafur and low dose oral leucovorin in patients with advanced colorectal carcinoma.

BACKGROUND

Protracted oral administration of tegafur (TG) and leucovorin (LV) attempts to simulate the continuous infusion of 5-fluorouracil, with a higher intracellular folate pool. In a prior dose-finding study with a fixed TG dose of 0.75 g/m2/day for a period of 21 days and continuous oral LV, the recommended dose of LV was 45 mg/day in 28-day cycles.

METHODS

Thirty-nine patients with histologic confirmation of adenocarcinoma of the colon or rectum, either advanced or metastatic disease, and who were not candidates for radical treatment were included in a Phase II study using this schedule.

RESULTS

One hundred sixty-three cycles of chemotherapy were delivered (median, 4 cycles per patient). Toxicity was observed in the form of diarrhea, which was severe in 12 patients (30.7%). Grade 3 (according to the World Health Organization criteria) oral mucositis was recorded in 7 patients (18%). Asthenia was severe in 10% of the patients. Recuperation from toxicity was rapid and managed primarily on an outpatient basis. Two complete (5.1%) and 13 partial (33.3%) responses were observed, with a global response index of 38.5% (95% confidence interval, 23.2-53.6%). The median overall survival was 11.3 months.

CONCLUSIONS

The results of this study show that an all-oral regimen of tegafur and leucovorin can obtain biochemical modulation, with a significant response rate, in patients with advanced colorectal carcinoma. Randomized trials are needed to assess the possible advantage of this regimen over intravenous schedules.