Pilot study of continuous low-dose 5-fluorouracil and cisplatin (FP regimen) for the treatment of metastatic breast cancer

Background. The effect of low-dose 5-fluorouracil (FU) and cisplatin therapy (FP regimen) against metastatic breast cancer was investigated. Methods. A pilot study of the FP regimen was performed in 11 patients with metastatic breast carcinoma who had previously received chemotherapy, including adriamycin, and/or hormonal therapy. Their median age was 56 years (range, 48‐72 years). Visceral metastases were present in all patients. FU, at a dose of 170 mg/m 2 per day, was administered for 28 days by continuous intravenous infusion. Cisplatin (7 mg/m 2 per day) was given intravenously on days 1‐5, 8‐ 12, 15‐19, and 22‐26. After a 2-week interval, this treatment was repeated. Results. Of the 11 patients assessable for tumor response to the FP regimen, 4 patients (36%; 95% confidence intervals [CI], 8%‐64%) achieved an objective response, with 1 showing a complete response and 3 showing a partial response. Median time to progression was 6.5 months (range, 4‐25 months). The median survival time from the initiation of the FP regimen was 11 months (range, 3‐25 months). Gastrointestinal and hematologic toxicity was mild. Conclusion. The FP regimen is promising for and has acceptable tolerance in patients with metastatic breast carcinoma refractory to previous anthracycline-containing chemotherapy.