title: [Impact of 2013 American Society of Clinical Oncology/College of American Pathologist guidelines on borderline immunostaining results for HER2: a retrospective study on HER2 FISH results in 1 780 cases of invasive breast cancers].
abstract: OBJECTIVE
  To analyze the impact of the revised 2013 American Society of Clinical Oncology/College of American Pathologist(ASCO/CAP)HER2 testing guidelines on the status of HER2 and its clinical significance in invasive breast cancers by fluorescent in situ hybridization(FISH).
  
  
  METHODS
  One thousand seven hundred and eighty invasive breast cancer cases with equivocal 2+ immunostaining detected by FISH were retrospectively selected from 2010 to 2014, and the HER2/CEP17 dual-probe results were evaluated according to both the 2007 and 2013 ASCO/CAP guidelines for comparative analysis.
  
  
  RESULTS
  Among the 1 780 IHC HER2 (2+ ) invasive breast cancers, the number of HER2 positive, equivocal and negative case were 310(17.41%), 66(3.71%)and 1 404(78.88%) respectively, basing on the 2007 guidelines; whereas basing on the 2013 ASCO/CAP HER2 guidelines, the number of HER2 positive, equivocal and negative case was 360 (20.22%), 182 (10.23%)and 1 238 (69.55%) respectively. Compared with the 2007 guidelines, the proportion of positive and equivocal cases were higher in the 2013 guidelines (17.41% versus 20.22%, 3.71% versus 10.23% respectively), while the proportion of negative cases was lower(78.88% versus 69.55%).
  
  
  CONCLUSIONS
  Using the 2013 ASCO/CAP guidelines could lead to an increase in positive and equivocal cases, and a decrease in negative cases. The increase can probably be attributable to the inclusion of HER2 copy number besides HER2/CEP17 ratio as positive criteria, and it improves the accuracy and may be of important value for screening more population who benefit from HER2 targeting treatment; however the benefits for HER2 positive with low HER2 copy number and the clinical significance of the equivocal cases need to be further investigated.
authors: Department of Pathology, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
authors: Y
authors: Y
authors: Xu
authors: Q M
authors: QM
authors: Bai
authors: F
authors: F
authors: Yang
authors: X L
authors: XL
authors: Zhu
authors: Y M
authors: YM
authors: Lu
authors: J
authors: J
authors: Zhang
authors: W T
authors: WT
authors: Yang
authors: X Y
authors: XY
authors: Zhou
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008495:Medical Oncology; D017410:Practice Guidelines as Topic; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D012189:Retrospective Studies; D012955:Societies, Medical; D014481:United States
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases