Aims and background: Trastuzumab-based therapy has improved survival of women with human epidermal growth factor receptor 2 (HER2)-overexpressing metastatic breast cancer.
Study design: From September 2002 to July 2006, 45 women with metastatic breast cancer HER2 3+, or 2+ and positive for HER2 gene amplification, were enrolled in the study and received a combination therapy with vinorelbine, 25 mg/m2 weeks 1 and 2, plus trastuzumab, 4 mg/kg loading dose and then 2 mg/kg weekly, in a three weeks cycle. Eligibility criteria included measurable disease and a baseline ejection fraction > or = 50%. Forty-two percent of the patients were not pretreated, whereas 58% had received a previous chemotherapy regimen for metastatic disease, including anthracyclines and/or taxanes (47%), and trastuzumab plus taxol (11%).
Results: We observed 14 (31%) complete responses and 21 (47%) partial responses, with an overall response rate of 78%. Stable disease > 6 months was assessed for 5 (11%) patients with a clinical benefit of 89%. Five (11%) patients progressed. With a median follow-up of 11 months, median time to progression was 9 months and median duration of response was 7.6 months for complete remissions and 4 months for partial remissions. Median survival was 29 months.
Conclusions: In spite of a smaller dose intensity of vinorelbine than previously reported, the regimen evaluated was notably effective in terms of response rate, time to progression and survival, with very mild toxicity.