title: Efficacy and safety of trastuzumab combined with chemotherapy for first-line treatment and beyond progression of HER2-overexpressing advanced breast cancer.
abstract: OBJECTIVE
  To observe the efficacy and safety of trastuzumab combined with chemotherapy in patients with human epidermal growth factor receptor 2 (HER2)-overexpressing advanced breast cancer.
  
  
  METHODS
  A total of 90 patients with HER2-overexpressing advanced breast cancer were enrolled in this study. All patients were diagnosed with ductal invasive breast cancer by pathological analysis, and were aged between 31-73 years with a median of 51 years. HER2-positivity was defined as 3(+) staining in immunochemistry or amplification of fluorescence in situ hybridization (FISH, ratio ≥2.0). Trastuzumab was administered in combination with chemotherapy as first-line treatment and beyond progression as a secondline, third-line, and above treatment in 90, 34, 14, and 6 patients, respectively. The chemotherapy regimen was given according to normal clinical practice. The response rate was evaluated every two cycles, and the primary endpoints were progression-free survival (PFS) and overall survival (OS). Survival curves were estimated by using Kaplan-Meier graphs and were compared by using log-rank test statistics. Multivariate analysis was done using Cox's proportional hazards regression model, and the level of significance was P<0.05.
  
  
  RESULTS
  All 90 patients received at least one dose of trastuzumab, and efficacy could be evaluated in 85 patients. The median follow-up was 50 months. In total, 72 (80.00%) patients had visceral metastasis, and 43 (47.78%) patients had progressed after one or more extensive chemotherapy regimens for metastatic diseases. The median PFS for first-line trastuzumab was 10 months (range, 2-59 months), and the median OS after metastasis or initially local advanced disease was 22 months (range, 2-116 months).
  
  
  CONCLUSIONS
  Trastuzumab combined with chemotherapy was active and well-tolerated as a first-line treatment and even beyond progression in HER2-overexpressing advanced breast cancer as a second-line or third-line treatment. However, its efficacy is certainly less beyond this point.
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Huiping
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Shao
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Guohong
authors.initials: G
authors.lastname: Song
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xiaoran
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Breast Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liang
keywords: Trastuzumab; advanced breast cancer; chemotherapy; efficacy and safety