Long-Term, weekly One-Hour Infusion of Paclitaxel in Patients with Metastatic Breast Cancer: A Phase II Monoinstitutional Study

Abstract

Aims and background A dose-dense therapy with weekly paclitaxel given as a 1-hr infusion yielded a 53% overall response rate in breast cancer patients resistant to anthracyclines, with a remarkable lack of neutropenia (Seidman, 1998). We performed a monoinstitutional phase II trial in order to confirm these interesting results. Patients and methods Eligibility criteria included advanced breast cancer and no taxane pretreatment. Paclitaxel was administered weekly at the dose of 90 mg/m2 (60 mg/m2 in patients at high risk of toxicity) by 1-hr iv infusion. Fifty-eight patients entered the trial. Median age was 54 years (range, 38-72). Performance status was good (median 1; range, 0-2). Fifty-two patients were pretreated with anthracyclines. Results A total of 1,004 weekly paclitaxel infusions were administered (median, 19 per patient; range, 4-43). The median delivered dose intensity was 67.4 mg/m2/week (range, 43-86). Twenty-eight of the 58 assessable patients obtained an objective response (48%), 15 had stable disease (26%) and 15 progressed (26%). The overall response rate was 48% (95% confidence interval, 35-61%) with 5 complete responses (8%). In anthracycline-pretreated patients, 23/52 (44%) responses were observed. Median duration of response was 5 months (range, 3-27). Toxicity was acceptable apart from a case of pulmonary embolism in a 70-year-old patient, 1 case of congestive heart failure in an anthracycline-pretreated patient aged 64, and 9 cases of G3 neutropenia. Peripheral neuropathy was observed in 38 patients (64%), usually of a mild grade; alopecia in 45 patients (78%) and onychopathy in 16 (28%), usually of a mild grade apart from 2 cases requiring treatment interruption. Tachycardia and atrial fibrillation occurred in a 55-year-old woman. Conclusions Our data seem to confirm the activity and safety of this approach even in a heavily pretreated population of patients. Its combination with other active drugs needs to be further investigated in clinical trials.