Purpose: To determine the maximum tolerated doses, toxicities, and therapeutic effect of an oral chemotherapy regimen consisting of uracil-ftorafur, etoposide, and leucovorin for metastatic breast cancer.
Patients and methods: The regimen consists of 28-day cycles of uracil-ftorafur, etoposide, and leucovorin administered orally on days 1-14. The dose of etoposide was fixed at 50 mg/m2/day, and uracil-ftorafur was escalated in 50 mg/m2/day increments from 200 to 350 mg/m2. Leucovorin, was used at a dose of 90 mg/day. Eligibility criteria required prior treatment with a taxane or anthracycline.
Results: A total of 23 patients were enrolled. Twenty patients are assessable for toxicity and 16 patients are assessable for response. All non-hematologic toxicities were grade 1 or 2. Three hematologic dose-limiting toxicities (DLTs) were observed. Partial responses were seen in 6 of 16 (37.5%, 95% confidence interval 15%, 85%) of assessable patients with durations ranging from 4 to 20 months. Stable disease was observed in 4 of 16 (25%) of patients with durations from 4 to 12 months. Median time to progression was 10.5 months. An intent to treat analysis revealed a response of 26%.
Conclusion: The recommended dose and schedule of this combination is uracil-ftorafur 350 mg/m2, leucovorin 90 mg/day, and etoposide 50 mg/m2 for two consecutive weeks in a 4-week cycle. This all-oral regimen is well tolerated and demonstrates encouraging efficacy in a cohort of heavily pretreated patient with metastatic breast cancer.