SummaryBackground: The protracted continuous infusion (PCI) of 5-fluorouracil (5-FU) has proven in several studies an active and well tolerated treatment for advanced, pretreated breast cancer. Navelbine has also activity in this setting.Patients and methods: Heavily pretreated patients with metastatic breast carcinoma were eligible for the study. Treatment consisted of 5-FU 250 mg/m 2 given as a PCI by an elastomeric pump and navelbine 20 mg/m 2 on days 1 and 8, every four weeks. Eighty-three patients (median age 54 years; range 32-82 years) entered the study. The median number of metastatic tumour sites was 2, with visceral involvement in 56 patients. Apart from five patients with contraindications, all