Fifty patients with advanced breast cancer (21 undergoing first and second stage palliative treatment: group 1, and 29 undergoing stage three or more: group 2), were included in a phase II trial with administration of a combination relay chemotherapy consisting of cisplatin (100 mg/m2/day) and fluorouracil (1,000 mg/m2/day), in continuous perfusion during 4 days, in cycles of five days repeated every three weeks (mean duration: 12 weeks). Toxicity was frequent and severe (a total of 17 treatments discontinued, and five deaths, 3 in group 1, 2 in group 2). The main manifestations of intolerance were threefold: haematological and leucopenia, in almost half of the patients, including 2 severe with 1 case of infectious complication and 4 thrombopenias requiring discontinuation of the treatment, including 2 with a severe haemorrhagic syndrome; cardiovascular, with three deaths due to heart failure; renal, most of the time laboratory tests disorders with 1 clinical syndrome. An objective response of more than fifty p. cent was obtained in five patients in group 1 (29.4%) and 3 patients in group 2 (11.1%); it lasted an average of 6.5 months and varied according to the locations: nodes (43%), liver (40%), pleuro-pulmonary (22%). Responses were obtained (13%) for lesions which resisted to previous chemotherapy. Five patients (14%) presented a functional improvement. The survival (mean = 4.8 months) was correlated, in group 1, to initial life conditions (p = 0.01) and was longer in group 1 for menopausal patients who had well tolerated the treatment (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)