Aims and background Paclitaxel, a microtubule inhibitor, is one of the most active drugs in metastatic breast cancer. A weekly schedule, at a median dose-intensity of 91 mg/m2, is effective and has less side effects than a 3-week schedule. In this phase II study, we evaluated the toxicity and the activity of weekly 1 hr paclitaxel infusions in metastatic breast cancer patients. Study design Between February 1999 and February 2001, 26 patients with metastatic breast cancer were treated with weekly paclitaxel (60–90 mg/m2/1 hour iv infusion/weekly). The treatment was planned to continue until disease progression or prohibitive toxicity; in patients with responsive or stable disease, paclitaxel was stopped after 6 months of therapy. Results At a median follow-up of 18.7 months (range, 6.8–30.8), all patients are assessable for response and toxicity. We obtained 8 partial responses (30.8%), 8 stable disease (30.8%) and 10 disease progression (38.4.%). The overall response was 30.8% (95% CI, 13.1–48.5). The median duration of response was 7.6 months (range, 1.8–12.4); median time to progression was 4.86 months (range, 1.4–12.4); median overall survival was 9.9 months (range, 1.7–29.2+). Treatment was well tolerated. Hematological toxicity was mild and only one patient developed grade 3 anemia. Two patients experienced grade 3 cardiovascular toxicity; both had received anthracycline-based regimens. Conclusions In our experience, weekly administration of paclitaxel shows a substantial degree of activity even in pretreated metastatic breast cancer patients. The toxicity profile is favorable.
Circulating tumor cells as an early predictive marker of disease progression in metastatic breast cancer patients
