title: A comparative assessment of HER2 status in operable breast cancer by real-time RT-PCR and by immunohistochemistry.
abstract: BACKGROUND
  The most commonly used methods for detecting HER2 gene amplification in breast cancer are immunohistochemistry and fluorescence in-situ hybridization. The aim of this retrospective study was to assess HER2 expression by real-time RT-PCR.
  
  
  METHODS
  Expression of HER2 was analyzed by real-time RT-PCR and immunohistochemistry in specimens of invasive ductal breast cancer tissue obtained from 131 women during radical mastectomy.
  
  
  RESULTS
  There was a highly significant difference in mean relative gene expression between HER2-positive and HER2-negative patients as assessed by immunostaining (22.10+/-41.89 vs. 3.17+/-8.76; p<0.001). With a median follow-up of 56 months, the cancer-specific survival of HER2-positive patients assessed by RT-PCR was worse in all cases and in the node-positive group. In multivariate analysis, HER2 status was an independent prognostic factor in all patients.
  
  
  CONCLUSIONS
  Real-time RT-PCR is a valuable method for determining HER2 status, but the selection of the cut-off point of the relative gene expression differentiating between HER2-negative and -positive tumors is essential.
authors.affiliation: Department of Chemotherapy, Medical University of Łódź, Copernicus Memorial Hospital, Łódź, Poland. piotrpo@mp.pl
authors.forename: Piotr
authors.initials: P
authors.lastname: Potemski
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Płuciennik
authors.forename: Andrzej K
authors.initials: AK
authors.lastname: Bednarek
authors.forename: Renata
authors.initials: R
authors.lastname: Kusińska
authors.forename: Grazyna
authors.initials: G
authors.lastname: Pasz-Walczak
authors.forename: Dorota
authors.initials: D
authors.lastname: Jesionek-Kupnicka
authors.forename: Cezary
authors.initials: C
authors.lastname: Watala
authors.forename: Radzisław
authors.initials: R
authors.lastname: Kordek
mesh_terms: D000328:Adult; D000368:Aged; D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000401:mortality; D018270:Carcinoma, Ductal, Breast / Q000235:genetics* / Q000378:metabolism* / Q000401:mortality; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005784:Gene Amplification; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011044:Poland / Q000453:epidemiology; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate
chemical_list: D017931:DNA Primers; D018719:Erb-b2 Receptor Tyrosine Kinases