L-folinic acid and 5-fluorouracil in the treatment of advanced breast cancer: A phase II study

Abstract

Background: The combination of 5-fluorouracil (5-FU) and folinic acid (FA) is an active combination for the treatment of advanced breast cancer (ABC). Theoretically, the biologically active isomer of FA, l-FA, should be more effective than racemic FA in modulating 5-FU activity. Patients and methods: Thirty-three patients (pts) with ABC, all previously treated with an anthracycline-based combination for advanced disease were treated with l-FA: 100 mg/m2 i.v. and 5-FU: 370 mg/m2 i.v. for 5 consecutive days every 4 weeks. Results: Three complete remission (CR) and 11 partial remission (PR) were obtained for an overall response rate of 42% (95% Cl = 25-59). Median duration of response was 10 months, median survival was 15 months for responders, 11 months for NC and 3 for PD. Eleven pts experienced a WHO grade III-IV oral mucositis (33%), 6 pts had grade III and one grade IV diarrhea, two pts had grade IV neutropenia resulting in one toxic death. Conclusions: In this heavily pretreated population of pts with ABC, this regimen showed an interesting activity with substantial toxicity. Both the response rate and the pattern of side-effects seem similar to those experienced with the racemic mixture of d,l-FA. Modulated 5-FU warrants an increasing consideration in the treatment of breast cancer.