title: Prognostic Significance of High Expression of ER-beta in Surgically Treated ER-Positive Breast Cancer Following Endocrine Therapy.
abstract: OBJECTIVE
  This study evaluated estrogen receptor (ER)-beta mRNA and ER-beta protein expression and its prognostic implications in hormone receptor-positive breast cancer.
  
  
  METHODS
  Paraffin sections from 139 hormone receptor-positive breast cancer cases were prepared. The expression of ER-beta mRNA and protein were analyzed by branched-chain assay and immunohistochemistry (IHC), respectively.
  
  
  RESULTS
  The Allred score of ER-beta IHC was correlated with smaller tumor size (p=0.043), the Allred score of ER-alpha IHC (p<0.001), and the Allred score of progesterone receptor (PR) IHC (p=0.022) but not with the HER2 IHC score. ER-beta mRNA level was correlated with PR mRNA levels (p<0.001) but not with the Allred score of ER-beta IHC, ER-alpha IHC, and PR IHC, nor with the HER2 IHC score and ER-alpha mRNA level. In survival analysis, high expression of ER-beta mRNA was associated with worse disease-free survival along with poor differentiation, lymph node metastasis and absence of PR protein expression in univariate analysis (p=0.040, p=0.002, p=0.018, and p=0.007, respectively) and multivariate analysis (p=0.044, p=0.002, p=0.035, and p=0.007, respectively).
  
  
  CONCLUSIONS
  High expression of ER-beta mRNA is an independent predictor of disease recurrence in hormone-receptor-positive breast cancer.
authors.affiliation: Department of Hospital Pathology, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Tae-Jung
authors.initials: TJ
authors.lastname: Kim
authors.forename: Ahwon
authors.initials: A
authors.lastname: Lee
authors.forename: Yeong-Jin
authors.initials: YJ
authors.lastname: Choi
authors.forename: Byung Joo
authors.initials: BJ
authors.lastname: Song
authors.forename: Hyeon Woo
authors.initials: HW
authors.lastname: Yim
authors.forename: Chang Suk
authors.initials: CS
authors.lastname: Kang