Trastuzumab with either docetaxel or vinorelbine as first-line treatment for patients with HER2-positive advanced breast cancer: a retrospective comparison

BACKGROUND: Combinations of trastuzumab with either docetaxel or vinorelbine are considered valuable treatment options for HER2-positive metastatic breast cancer patients. We performed a retrospective comparison of the clinical outcomes associated with either one of these combinations. METHODS: From a multi-institutional database we retrieved 179 patients treated with either docetaxel or vinorelbine plus trastuzumab as first-line therapy for HER2-positive advanced breast cancer. RESULTS: Docetaxel-trastuzumab was superior to vinorelbine-trastuzumab in terms of response rate (RR: 77 vs 57%, p = 0.01) and median overall survival (OS: 35 vs 23 months, p = 0.04), but not in median time to progression (TTP: 12 vs 10 months, p = 0.53). At multivariate analysis, type of treatment was not associated with TTP but was an independent predictor of OS, with a significant reduction in the risk of death in favor of docetaxel-trastuzumab (HR 0.474, 95% IC 0,303-0.742, p < 0.01). CONCLUSION: Docetaxel or vinorelbine, when combined with trastuzumab, provide excellent rates of tumor control in patients with previously untreated HER2-positive advanced breast cancer. Docetaxel may offer some advantage in terms of response rate and resulted in a significantly prolonged overall survival, which, because of the retrospective design of our study, deserves further investigation in prospective trials.