Weekly paclitaxel, 5-fluorouracil and folinic acid with granulocyte colony-stimulating factor support in metastatic breast cancer patients: a phase II study.

We conducted a phase II study to determine the activity and tolerability of weekly paclitaxel, 5-fluorouracil (5-FU) and folinic acid plus granulocyte colony-stimulating factor (G-CSF) support in anthracycline-pre-treated or -resistant metastatic breast cancer patients. The phase II study was designed following the Simon optimal-two stage method. Patients received paclitaxel 80 mg/m, folinic acid 10 mg/m and bolus infusion of 5-FU 300 mg/m every week plus G-CSF on day 3 for 24 consecutive weeks in the absence of disease progression. From May 1998 to May 2000, 51 patients entered the study. Patients received a median relative dose intensity of 97.5% (range 81-100%). No severe toxicities were observed. Seven patients (14%) experienced neutropenia grade 2. Seven patients (14%) experienced grade 2 anemia. Two patients (4%) experienced severe asthenia. Three out of 50 evaluable patients [6%, 95% confidence interval (CI) 2-12.6%] showed a complete response, whereas 23 (46%, 95% CI 32.2-59.8%) had a partial response, with an overall response rate of 52% (95% CI 38.2-65.8%). In addition, eight patients (15.7%) had stable disease. In the 13 patients untreated for metastatic disease, the overall response rate was 92.3% (CI 77.8-100), with one complete response and 11 partial responses (84.6% CI 65-100%). In the whole group, the median time to progression and overall survival were 8 (range 1-18) and 14 months (95% CI 11-17), respectively. Thus, in metastatic breast cancer patients pre-treated with anthracyclines, the weekly administration of paclitaxel, 5-FU and folinic acid with G-CSF support seems to be extremely tolerable and active.