title: Association of CYP2C19 polymorphisms with survival of breast cancer patients using tamoxifen: results of a meta- analysis.
abstract: BACKGROUND
  Previous studies accessing the association of CYP2C19 with outcomes of patients using tamoxifen for breast cancer have yielded conflicting results. The aim of this meta-analysis is to obtain a more precise estimate of effects of CYP2C19 polymorphisms and to clarify their effects on survival of the breast cancer patients using tamoxifen.
  
  
  METHODS
  A systematic search of PubMed and Embase was performed, comparing patients with or without CYP2C19*2 and CYP2C19*17, relevant articles searched for. The following outcomes were included from the eligible studies: disease-free survival (DFS) and overall survival (OS), expressed by hazard ratios (HR) with corresponding 95% confidence interval (CI). Subgroup analysis by genotypes was also performed. Pooled estimates were calculated using random-effect model in accordance to the heterogeneity.
  
  
  RESULTS
  Six studies met the inclusion criteria. The integrated OR on the association between CYP2C19 and DFS, calculated by the random-effect model, was 0.54 (95%CI=0.34-0.84, p=0.013). Subgroup analysis showed that both CYP2C19*2 and CYP2C19*17 were associated with increased survival. The pooled results of two studies for OS were OR=0.46 (95%CI=0.21-1.01, p=0.233).
  
  
  CONCLUSIONS
  This meta-analysis suggests that the CYP2C19*2 and CYP2C19*17 genotypes are associated with increased survival in breast cancer patients using tamoxifen.
authors.affiliation: Department of Pharmacy, Kunming General Hospital of Chengdu Military Command, Kunming, People's Republic of China E-mail : xuguili2006@126.com.
authors.forename: Lan
authors.initials: L
authors.lastname: Bai
authors.forename: Juan
authors.initials: J
authors.lastname: He
authors.forename: Gong-Hao
authors.initials: GH
authors.lastname: He
authors.forename: Jian-Chang
authors.initials: JC
authors.lastname: He
authors.forename: Fan
authors.initials: F
authors.lastname: Xu
authors.forename: Gui-Li
authors.initials: GL
authors.lastname: Xu
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000401:mortality*; D016022:Case-Control Studies; D065731:Cytochrome P-450 CYP2C19 / Q000235:genetics*; D005260:Female; D006801:Humans; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate; D013629:Tamoxifen / Q000627:therapeutic use*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19