Phase II study of oral tegafur-uracil and folinic acid as first-line therapy for metastatic colorectal cancer: Taiwan experience

Background: Tegafur-uracil has become an important regimen in the treatment of metastatic colorectal cancer. Tegafur is a prodrug that is converted to 5-fluorouracil (5-FU) and has been reported to be less toxic and to have a higher therapeutic index. The additional advantage of tegafur is oral admi nistration, an important consideration to improve the quality of life in th ese patients. Tegafur in combination with uracil is thought to have greater anti-tumor activity due to the inhibitory effect of uracil on the degradat ion of 5-FU by hepatic dihydropyrimidine dehydrogenase. Tegafur with folini c acid has been reported with modest efficacy and acceptable toxicity. The purpose of this study was to evaluate the effectiveness and toxicity profil e of oral tegafur-uracil plus folinic acid in Chinese patients with metasta tic colorectal cancer. Methods: Between May 1998 and August 1999, 40 patients with metastatic colo rectal carcinoma were enrolled in this study. All the patients had to have measurable lesions. The initial dose of tegafur-uracil was 300 mg/m(2)/day for 28 days, followed by a 7-day rest period. Folinic acid was administered orally at a dose of 60 mg/day concurrently with tegafur-uracil. For patien ts with neutrophil count <1500/<mu>l or a platelet count <100 000/<mu>l aft er treatment, the treatment was postponed for a maximum of 2 weeks. After t hat time, if the neutrophil count was 1000-1500/mul and the platelet count was 70 000-100 000 mul, the dose of tegafur-uracil was reduced by 50%, and if lower values resulted, the treatment was discontinued. Results: Forty patients received a total of 318 courses of treatment and a response rate of 32.5% (95% CI, 18-47%), including five complete remissions and eight partial remissions, was achieved. Toxicity was mild and generall y tolerable. Gastrointestinal toxicities, including diarrhea, nausea and vo miting, were the major side effects. Seven incidences (17.5%) of grade 3-4 gastrointestinal toxicity were observed. Hematological toxicities were mini mal with no evidence of severe (grade 3 or 4) leukopenia and thrombocytopen ia. No episode of hepatic, renal, cardiac or neurological toxicity occurred . Two patients (5%) developed transient painful fissuring erythroderma over their palms and soles (the hand-foot syndrome). Conclusions: The data from our study indicate that oral tegafur-uracil plus folinic acid is an active and tolerable first-line treatment for Chinese p atients with metastatic colorectal cancer, with the additional advantage of being easily administered at home.