Taxanes Plus Trastuzumab Compared To Oral Vinorelbine Plus Trastuzumab in HER2-Overexpressing Metastatic Breast Cancer

Background: This retrospective analysis was planned as a direct comparison of taxanes plus trastuzumab to the less toxic combination of oral vinorelbine (OV) plus trastuzumab as a first-line therapy for metastatic HER2-positive breast cancer. Patients and Methods: Patients (n = 76) receiving either taxanes (group A) or OV (group B) in combination with trastuzumab were identified from a breast cancer database. Progression-free survival (PFS) was defined as the primary study endpoint; secondary endpoints were overall survival (OS), response rate (RR), incidence of brain metastases, and brain metastases-free survival (BMFS). Results: 36 patients received taxanes and 40 patients OV in combination with trastuzumab. At a median follow-up of 47.5 months, median PFS was 7 months (group A) and 9 months in group B (log-rank; non-significant), respective numbers for OS were 49 and 59 months (p = 0.033). The incidence of brain metastases did not differ significantly between the 2 treatment groups, whereas BMFS was significantly longer in patients receiving OV. Conclusions: OV plus trastuzumab yielded similar results in terms of PFS and RR and was superior in terms of OS and BMFS. These results add to the growing body of evidence that vinorelbine is a viable alternative to taxanes in HER2-positive metastatic breast cancer.