Paclitaxel in combination with weekly 24-hour infusional 5-fluorouracil plus leucovorin in the second-line treatment of metastatic breast cancer: results of a phase II study.

Purpose: To evaluate the antitumor activity in terms of response rate (RR), time to progression (TTP) and survival of paclitaxel in combination with weekly 24-hour infusional 5-fluorouracil (5-FU)/leucovorin in pretreated metastatic breast cancer (MBC).

Patients And Methods: Fifty-four patients with bidimensionally measureable disease were included during phase II. Thirty-two had anthracycline resistant disease. Treatment consisted of 5-FU (24-hour i.v. infusion) 2.0 g/m2, leucovorin (two-hour i.v. infusion prior to 5-FU) 500 mg/m2, weekly for six weeks (day 1, 8, 15, 22, 29, 36) and paclitaxel (three-hour i.v. infusion) 175 mg/m2 was administered additionally on days 1 and 22, q 50 days.

Results: We observed complete remissions in 4% of patients (2 of 54), partial remissions in 55% (30 of 54), stable disease in 37% (20 of 54) and progressive disease in 4% (2 of 54). The overall RR was 59% (95% CI 48%-72%). The RR in 32 patients with anthracycline resistant disease was 59% (19 of 32). The median duration of response was 12 months (3-22), median TTP eight months (2-22) and median survival time 15 months (2-28). Neutropenia was common, but of CTC grade 2 or 3 in most patients. Nonhematologic toxicities mostly consisted of CTC grade 1 and 2 myalgia, diarrhea, mucositis, nausea and vomiting.

Conclusions: Paclitaxel combined with weekly 24-hour infusional 5-FU/leucovorin is well tolerated in the second line treatment of MBC. High efficacy was documented even in the treatment of anthracycline resistant disease, which warrants further evaluations.