5FU Continuous Infusion in Heavily Pretreated Advanced Breast Cancer Patients

Background: Despite advances in the first- and secondline treatment of advanced breast cancer, optimal therapy thereafter remains controversial. Treatment of heavily pretreated patients is not standardized, often of low efficacy, and limited by comorbidity. In these patients, an effective treatment with low toxicity is needed. Patients and Methods: We retrospectively analyzed all metastatic breast cancer patients treated with 5-fluorouracil as continuous infusion (CI-5FU) with daily doses of 150–300 mg/m2. Results: 43 patients were treated with CI-5FU until disease progression. The median number of metastatic sites was 3. Most patients were heavily pretreated with a median of 3 palliative chemotherapies (range 1–11). 42 patients were evaluable for objective response; among them 5 (12%) showed a partial response (PR) and 6 (15%) showed stable disease (SD) lasting at least 6 months, leading to a clinical benefit (CB) rate (complete response + PR + SD ≧ 6 months) of 27%. The median time to progression of patients with CB was 10 months (range 3–22). Overall survival of all patients from the start of CI-5FU was 8 months (range 1–75) and from the time of first metastases 42 months (range 9–281). Toxicity was low even in patients with hepatic insufficiency. Conclusion: CI-5FU showed a positive efficacy/toxicity ratio. Taking into account the high number of previous treatments, it results in a remarkable CB rate of 27%.