title: [Use of the new 2013 ASCO/CAP guidelines to study HERS status by fluorescence in situ hybridization in patients with breast cancer].
abstract: Despite the long-term history of HER2 testing in breast cancer (BC), the results of its study are frequently interpreted ambiguously. The introduction of the new 2013 ASCO/CAP guidelines is aimed to further optimize HERS testing in view of new scientific evidence for the biological characteristics of BC.
  
  
  OBJECTIVE
  to study the results of assessing HERS2 status in patients with the questionable level of protein expression according to the 2007 versus 2013 ASCO/CAP criteria.
  
  
  METHODS
  Biopsy specimens from 572 patients diagnosed with BC after immunohistochemical examination, including HER2 status assessment, were investigated by fluorescence in situ hybridization.
  
  
  RESULTS
  The use of the new 2013 ASCO/CAP criteria versus the previous criteria to determine intratumor heterogeneity, HER2 gene copy number, and the so-called chromosome 17 polysomy was ascertained to cause a statistically significant increase in HER2-positive cases from 25 to 42.5% (OR=2.2178; 95% CI, 1.8254-2.6950; р=0.0005).
  
  
  CONCLUSIONS
  The use of the new guidelines additionally permits effective therapy in patients with BC, which may be another step to improve survival in this large patient group.
authors.affiliation: Moscow City Cancer Hospital Sixty-Two, Moscow Department of Healthcare, Moscow, Russia.
authors.forename: I A
authors.initials: IA
authors.lastname: Demidova
authors.affiliation: Moscow City Cancer Hospital Sixty-Two, Moscow Department of Healthcare, Moscow, Russia.
authors.forename: E O
authors.initials: EO
authors.lastname: Tsepenshchikova
authors.affiliation: Moscow City Cancer Hospital Sixty-Two, Moscow Department of Healthcare, Moscow, Russia.
authors.forename: M B
authors.initials: MB
authors.lastname: Gikalo
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002869:Chromosome Aberrations; D005260:Female; D018628:Gene Dosage / Q000235:genetics*; D017408:Guidelines as Topic; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human