title: Clinicopathological characteristics and prognostic value of cancer stem cell marker CD133 in breast cancer: a meta-analysis.
abstract: BACKGROUND
  The association of CD133 overexpression with clinicopathological significance and prognosis in patients with breast cancer remains controversial. We thus performed a meta-analysis to evaluate the role of CD133 expression in the development and prognosis of breast cancer.
  
  
  METHODS
  The databases PubMed, Embase, and Cochrane Library (updated to August 1, 2016) were searched. Pooled odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (95% CI) were used to evaluate the impact of CD133 expression on clinicopathological features, overall survival, and disease-free survival.
  
  
  RESULTS
  A total of 1,734 patients from 13 studies were subject to final analysis. The results showed a significant association between overexpression of CD133 and estrogen receptor status (OR 0.35, 95% CI 0.18-0.70), progesterone receptor status (OR 0.56, 95% CI 0.43-0.74), human epidermal growth factor-2 status (OR 1.81, 95% CI 1.33-2.45), lymph node metastasis (OR 1.98, 95% CI 1.34-2.92), and tumor histological grade (OR 1.79, 95% CI 1.26-2.54) in breast cancer. However, no significant correlation was found between upregulation of CD133 expression and onset age (OR 1.03, 95% CI 0.70-1.53) or tumor size (OR 1.29, 95% CI 0.80-2.09). Moreover, CD133-positive breast cancer patients had a higher risk of mortality (HR 1.91, 95% CI 1.21-3.03) and disease progression (HR 2.70, 95% CI 1.05-6.95).
  
  
  CONCLUSIONS
  This meta-analysis suggested that CD133 might be a predictor of clinical outcomes as well as prognosis and could be a potentially new gene therapy target for breast cancer patients.
authors.affiliation: Department of Breast Surgery.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Surgical Oncology, The First Hospital of China Medical University, Shenyang, Liaoning.
authors.forename: Songcheng
authors.initials: S
authors.lastname: Yin
authors.affiliation: Department of Breast Surgery.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Breast Surgery.
authors.forename: Weiguang
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Breast Surgery.
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Breast Surgery, China-Japan Union Hospital of Jilin University, Changchun, Jilin, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Xing
keywords: CD133; CSCs; biomarker; breast cancer; meta-analysis; prognosis