title: Epidermal growth factor receptor changes during breast cancer metastasis.
abstract: BACKGROUND
  Since the anti-HER2 monoclonal antibody trastuzumab made its triumphant advance into breast cancer therapy, new selective agents, including pan-HER inhibitors are entering clinical practice.
  
  
  METHODS
  This study investigates the expression of the four HER-family members, HER1-4, in 48 primary breast carcinomas (PBC) and corresponding distant metastases (CDM) by immunohistochemistry and fluorescence in situ hybridisation.
  
  
  RESULTS
  Concordance rate between PBC and CDM was 79% for HERI and HER2, 67% for HER3 and 56% or HER4. Expression of HER1-3 was associated with poor prognosis compared to HER-negative disease (p = 0.036). HER4 overexpression was associated with a better outcome (p = 0.003).
  
  
  CONCLUSIONS
  Though most tumours demonstrate a stable HER expression pattern, both loss and acquisition of HER receptor overexpression can occur during metastasis. HER4 overexpression predicts prolonged survival compared to receptor negative disease, while the opposite is true for HER1-3. Consequences for modem antibody therapy are discussed.
authors.affiliation: Department of Gynecology, Charité C. Virchow, 13353 Berlin, Germany. ilka.fuchs@charite.de
authors.forename: Ilka B
authors.initials: IB
authors.lastname: Fuchs
authors.forename: Ildiko
authors.initials: I
authors.lastname: Siemer
authors.forename: Helmut
authors.initials: H
authors.lastname: Bühler
authors.forename: Annette
authors.initials: A
authors.lastname: Schmider
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Henrich
authors.forename: Werner
authors.initials: W
authors.lastname: Lichtenegger
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schaller
authors.forename: Sherko
authors.initials: S
authors.lastname: Kuemmel
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D066246:ErbB Receptors / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D009362:Neoplasm Metastasis; D011379:Prognosis
chemical_list: D066246:ErbB Receptors