title: Estrogen receptor beta expression in invasive breast cancer.
abstract: The aim of this work was to determine the extent of estrogen receptor beta (ER-beta) expression in invasive breast cancer (BrCA) and whether ER-beta expression is correlated with response to adjuvant hormonal therapy with tamoxifen (AHTT). Immunohistochemical staining (IHC) for estrogen receptor alpha (ER-alpha) and ER-beta was performed on sections of formalin-fixed and paraffin-embedded tissue from 47 unselected invasive breast carcinomas (BrCA). IHC for ER-beta was also performed on sections of BrCA from 118 women who were treated with mastectomy and AHTT. Survival analysis was performed using the Kaplan-Meier method and the log-rank test. Of the 47 unselected BrCA, 17 (36%) were negative for ER-alpha and of these, 8 (47% of ER-alpha negative cases and 17% of all 47 patients) were ER-beta positive. Five of the 8 ER-alpha negative and ER-beta positive cases were positive for ER biochemically. There was no correlation between ER-beta positivity and overall survival in the unselected group. By contrast, in the group of women treated with AHTT, expression of ER-beta in more than 10% of cancer cells was associated with better survival (P = .0077), even in women with node-negative BrCA (P = .0069). In conclusion, our results show that a significant number of women with BrCA are positive for ER-beta only, and may be determined to be ER-negative when currently available IHC is used. ER-beta status is a significant predictor of response to AHTT in women with BrCA. Larger studies with multivariate analysis are needed to confirm these findings.
authors.affiliation: Department of Pathology, Baylor College of Medicine, and The Methodist Hospital, Houston, TX 77030, USA.
authors.forename: S
authors.initials: S
authors.lastname: Mann
authors.forename: R
authors.initials: R
authors.lastname: Laucirica
authors.forename: N
authors.initials: N
authors.lastname: Carlson
authors.forename: P S
authors.initials: PS
authors.lastname: Younes
authors.forename: N
authors.initials: N
authors.lastname: Ali
authors.forename: A
authors.initials: A
authors.lastname: Younes
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Younes
mesh_terms: D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D016019:Survival Analysis
chemical_list: D011960:Receptors, Estrogen