Phase II study of low-dose infusional 5-fluorouracil and paclitaxel (Taxol) given every 2 weeks in metastatic breast cancer.

Twenty-one patients with recurrent or metastatic breast cancer were treated with paclitaxel (Taxol) as a 1-hour infusion on day 1 only of a 14-day cycle. This treatment was followed by 5-fluorouracil (5-FU) via a portable home pump, through a central venous catheter at 350 mg/m2 per day over 24 hours for a total of 96 hours, on days 1 to 5 and again on days 8 to 12. Based on reported phase I trials in other organ system cancers, the first 5 patients were treated with paclitaxel at 150 mg/m2 every 2 weeks, but this was associated with excessive toxicity. Subsequent patients received paclitaxel at 135 mg/m2. The FACT-B scale was used to assess quality of life for patients on entry of the study and after three cycles. Treatment was well tolerated, with no grade III or IV hematologic toxicities. Grade III nonhematologic toxicities comprised one patient with fatigue, one with mucositis, and one with diarrhea. Grade IV nonhematologic toxicities included 1 hypersensitivity reaction to paclitaxel. Four of the 16 patients (25%) had pump-related problems resulting in disrupted 5-FU dosing in the home setting. The patients had the following responses to the treatment: complete response 0 (0%), partial response 6 (37.5%), stable disease 4 (25%), progression 4 (25%), unassessable 2 (12.5%)-1 anaphylaxis and 1 thrombocytopenia; overall response rate 6 of 16 (0.37; 95% CI, of 0.57). The median duration of survival was 14 months, 95% CI (5.6-18.24). The FACT-B was assessed in 14 patients at baseline and in 8 patients after 3 cycles. Quality of Life improved in 6 patients, no patients remained stable, and worsened in 2 patients. Biweekly paclitaxel with weekly 4-day continuous infusion 5-FU was associated with minimal toxicity but did not meet the target response rate of 60%. This response rate does not justify use of a complex home infusion of 5-FU.