Protracted continuous infusion of 5-fluorouracil in combination with doxorubicin, vincristine, and oral cyclophosphamide in advanced breast cancer

Phase I Trial of Uracil–Ftorafur, Leucovorin, and Etoposide: An Active All-oral Regimen for Metastatic Breast Cancer

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.

Clinical pharmacology of anticancer agents in relation to formulations and administration routes

In the past years, alternative administration routes and pharmaceutical formulations of anticancer agents have been investigated in order to improve conventional chemotherapy treatment. The impact of these adjustments on the pharmacokinetics and pharmacodynamics is discussed. A review of the literature shows many examples of alternative administration forms of anticancer agents with improved pharmacokinetics. Local administration routes have been investigated in order to reduce the systemic toxicity and to enhance the local efficacy of conventional chemotherapy. Oral administration of anticancer agents is preferred by patients for its convenience and its potential for outpatient treatment. In addition, oral administration facilitates a prolonged exposure to the cytotoxic agent. However, poor bioavailability and substantial interpatient variability are noted as limitations for oral chemotherapy. Increased tumour selectivity can also be achieved by the use of specific pharmaceutical formulations, such as liposomes and macromolecular drug conjugates. The composition of these formulations often determine the pharmacokinetic behaviour of the formulated drug. In conclusion, several alternative administration forms of anticancer agents have been designed in the past years, with the potential for improvement of conventional chemotherapy, however, more extensive clinical evaluation of these novel strategies is warranted to prove their real clinical value.

Randomized trial comparing protracted infusion of 5-fluorouracil with weekly doxorubicin and cyclophosphamide with a monthly bolus FAC regimen in metastatic breast carcinoma (SPM90)

Infusional 5-fluorouracil in advanced breast cancer has been associated with improved clinical response rates when compared with conventional bolus therapy. As a first line of chemotherapy in proven metastatic breast carcinoma, 258 women were randomly assigned to receive FAC consisting of 5-fluorouracil (F) 600 mg m(-2) intravenously (i.v.) over 1 h on days 1, 2 and 3, doxorubicin (A) 50 mg m(-2) i.v. bolus on day 1 and cyclophosphamide (C), 400 mg m(-2) i.v. bolus on days 1, 2 and 3 or 'FULON' consisting of 5-fluorouracil 250 mg m(-2) day(-1) continuously infused from day 1 to day 22, doxorubicin 15 mg m(-2) i.v. bolus on days 1, 8, 15 and 22 and cyclophosphamide 300 mg m(-2) i.v. bolus on days 1, 8, 15 and 22. Chemotherapy courses were administered 4-weekly for the bolus regimen and 6-weekly for FULON. Pretreatment characteristics were identical between the two groups. Response rates were 54% in the FAC arm and 53% in the FULON arm. Time to progression was 14 months in the FAC arm and 12 months in the FULON arm. Differences were not statistically significant. Median overall survival duration for all patients was 22 months. Haematological toxicity was more severe in the bolus-treated group (P = 0.05), as were nausea and vomiting (P < or = 0.01). We conclude that the two regimens appeared equally effective but have different toxicities.