Third- and Fourth-Line Chemotherapies including Paclitaxel and Bevacizumab for Metastatic Breast Cancer]

The present study was designed to estimate the clinical efficacy of bevacizumab(BV)combined with paclitaxel(PTX)(BVPTX) as third- and fourth-line therapies in 31 patients with metastatic breast cancer(MBC). Most patients were previously treated with docetaxel and/or epirubicin. Patients were intravenously treated with BV at 5-10mg/kg and PTX at 3-5mg/kg at 2-3week intervals, and when the effect of BV-PTX was low, other chemotherapeutic agents(CTAs)and/or trastuzumab (Tr)were additionally administered. Twelve MBC patients were treated with BV-PTX alone and 19 MBC patients were treat- ed with other CTAs and/or Tr in addition to BV-PTX. No serious adverse events were observed in any regimen. Three complete responses(9.7%), 4 partial responses(12.9%), 8 stable diseases(25.8%), and 16 progressive diseases(51.6%)were observed; the response rate was 22.6%, and the clinical benefit rate was 48.4%. The median progression-free survival(PFS) and median overall survival(OS)after the initiation of BV-PTX were 7.0 and 16.0 months, respectively. All 13 HER2-positive MBC patients were treated with Tr in addition to BV-PTX, and the OS and PFS were significantly higher in the BV-PTX+Tr+ CTAs group than in the BV-PTX+Tr group. In 18 HER2-negative MBC patients, PFS and OS were better in the BV-PTX+CTAs group than in the BV-PTX alone group, though this difference was not significant. Multivariate analyses demonstrated that an additional CTAs was a variable for significantly better PFS, and additional CTAs, Tr, and endocrine therapy were significant variables for better OS. These results indicated that additional CTAs and Tr should be combined with BV-PTX for third- and fourth-line chemotherapies.