title: Estrogen receptor-beta mRNA is associated with adverse outcome in patients with breast cancer.
abstract: OBJECTIVE
  Estrogen receptor (ER) is the prototype therapy predictive marker in oncology. The ER is now known to exist in two main forms with similar overall structure: ER-alpha and ER-beta. Both forms may be expressed in breast cancer. The aim of this study was to examine breast cancer outcome in relation to expression of ER-beta.
  
  
  METHODS
  In this investigation, we measured the expression of ER-alpha protein and ER-beta mRNA in 121 extracts of invasive breast cancer. Association of expression with clinical outcome was examined using Kaplan-Meier and Cox regression analyses.
  
  
  RESULTS
  While ER-alpha expression was associated with good patient outcome [hazard ratio (HR) for death from breast cancer 0.37; 95% confidence interval (CI) 0.17-0.84; p = 0.017], ER-beta predicted poor outcome (HR for death from breast cancer 2.49; 95% CI 1.10-5.63; p = 0.028).
  
  
  CONCLUSIONS
  Based on these findings, we conclude that ER-beta may have a different biological role from that of ER-alpha in breast cancer.
authors.affiliation: Conway Institute of Biomolecular and Biomedical Research, UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
authors.forename: G C
authors.initials: GC
authors.lastname: Markey
authors.forename: R
authors.initials: R
authors.lastname: Cullen
authors.forename: P
authors.initials: P
authors.lastname: Diggin
authors.forename: A D K
authors.initials: AD
authors.lastname: Hill
authors.forename: E W
authors.initials: EW
authors.lastname: Mc Dermott
authors.forename: N J
authors.initials: NJ
authors.lastname: O'Higgins
authors.forename: M J
authors.initials: MJ
authors.lastname: Duffy
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D047628:Estrogen Receptor alpha / Q000235:genetics; D047629:Estrogen Receptor beta / Q000235:genetics*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness / Q000235:genetics; D016016:Proportional Hazards Models; D012333:RNA, Messenger / Q000235:genetics*; D012044:Regression Analysis; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D012333:RNA, Messenger