title: Current technologies for HER2 testing in breast cancer.
abstract: BACKGROUND
  Molecular techniques play an increasingly important role in breast cancer detection and help in the prediction of prognosis and treatment response. HER-2/neu predicts the sensitivity of breast tumors to trastuzumab and lapatinib. Presently there are several ways to assess HER2 status at the protein level (e.g. ELISA), at the RNA level (RT-PCR, microarray) and at the DNA level (fluorescence in situ hybridization, chromogenic in situ hybridization (ISH), silver in situ hybridization or multiplex ligation-dependent probe amplification).
  
  
  METHODS
  This paper provides an overview of new developments in HER2 testing.
  
  
  RESULTS
  Although these techniques correlate well in comparative studies, discrepancies remain. Each technique has its own (dis)advantages and thus there is no real gold standard. Not surprisingly, there is no consensus at present on which of the protein- or gene-based techniques is superior, on the use of mono- or duo-probe ISH systems, nor on the use of manual or fully-automated staining- and scoring systems.
  
  
  CONCLUSIONS
  Until large clinical trials clearly point out one strategy as the best predictive one for trastuzumab response, the choice for a testing strategy will probably be based on local preferences which consider both practical and economic issues. Standardization, proper internal and external quality control assessment, laboratory accreditation and automation of tissue processing (autostainers) and interpretation methods (image analysis) will play an increasingly important role in HER2 testing.
authors.affiliation: Department of Pathology, University Medical Center Utrecht, The Netherlands. cmoelans@umcutrecht.nl
authors.forename: C B
authors.initials: CB
authors.lastname: Moelans
authors.forename: R A
authors.initials: RA
authors.lastname: de Weger
authors.forename: E
authors.initials: E
authors.lastname: Van der Wall
authors.forename: P J
authors.initials: PJ
authors.lastname: van Diest
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D055088:Early Detection of Cancer / Q000191:economics / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D009362:Neoplasm Metastasis; D011786:Quality Control; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases