Résumé : Previous small phase II trials have demonstrated that the combination of 5-fluorouracil (5FU) and cisplatin(CDDP) could have clinical activity in metastatic biliary tract cancer. This randomised phase II trial was designed to assess the activity and safety of a high-dose infusional weekly 5FU alone (HDFU) and the combination of 5FU, folinic acid (FA) and CDDP. Patients were included if they had histologically proven locally advanced or metastatic biliary tract carcinoma, World Health Organisation (WHO) performance status < or = 2, bilirubin <2 x upper normal limit, adequate haematological and renal functions and had not received prior chemotherapy, even in the adjuvant setting. Treatments: Arm A (HDFU) consisted of cycles of 5FU 3 g/m(2) intravenously (i.v.), 24 h infusion, weekly, for 6 weeks, followed by 1 week rest, every 7 weeks; Arm B (5FU+FA+CDDP) consisted of cycles of 5FU 2.0 g/m(2) i.v. with folinic acid 500 mg/m(2), 2 h-infusion, weekly, for 6 weeks, followed by 1 week rest plus cisplatin 50 mg/m(2), once every two weeks, for 6 weeks, followed by 1 week rest, every 7 weeks. From February 1997 to June 1999, 58 patients were randomised (29 in each arm). Patients had a median age of 58 years in Arm A and 62 years in Arm B, locally advanced disease was present in 21% of the patients in Arm A and 11% in Arm B. WHO performance status of 0/1/2 was noted in 48%/45%/7% of the patients in Arm A and 54%/43%/4% in Arm B. In both arms, the most common metastatic sites were the liver and peritoneum. Twenty-eight patients were eligible in each arm and one patient did not start the allocated therapy in Arm B. The median number of cycles was 2 [range 1-12] in Arm A and 2 [range 1-6] in Arm B. Responses for the eligible patients who started their allocated therapy were as follows: Complete Response (CR) 0% in Arm A, 4% in Arm B, Partial Response (PR) 7% in Arm A, 15% in Arm B resulting in an overall response rate [95% CI] of 7.1% in Arm A [0.9-23.5%] and 19% [6.3-38.1%] in Arm B. Disease stabilisation was observed in 46% in Arm A and 44% in Arm B. National Cancer Institute of Canada (NCIC) grade 3-4 adverse events (% of patients in Arm A/Arm B) were neutropenia 4%/26%, thrombopenia 0%/7%, stomatitis 0%/4%, vomiting 7%/14%, diarrhoea 0%/11% and neurotoxicity 4%/0%. There was one early toxic death in Arm B. The median overall survival (OS) [95% CI] was in Arm A/Arm B: 5.0 [4.0-7.4] months/8.0 [5.8-11.8] months and the median progression-free survival (PFS) was 3.3 [1.7-4.7] months/3.3 [2.3-6.7] months. Cisplatin in combination with 5FU+FA showed a higher activity than HDFU, but was more toxic. These results are not sufficient to start a phase III trial. However, our group is planning a phase III trial comparing 5FU+folinic acid versus the same schedule+oxaliplatin a platinum analogue.