title: Laboratory compliance with the American Society of Clinical Oncology/College of American Pathologists human epidermal growth factor receptor 2 testing guidelines: a 3-year comparison of validation procedures.
abstract: BACKGROUND
  The American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) published guidelines in 2007 regarding testing accuracy, interpretation, and reporting of results for HER2 studies. A 2008 survey identified areas needing improved compliance.
  
  
  OBJECTIVE
  To reassess laboratory response to those guidelines following a full accreditation cycle for an updated snapshot of laboratory practices regarding ASCO/CAP guidelines.
  
  
  METHODS
  In 2011, a survey was distributed with the HER2 immunohistochemistry (IHC) proficiency testing program identical to the 2008 survey.
  
  
  RESULTS
  Of the 1150 surveys sent, 977 (85.0%) were returned, comparable to the original survey response in 2008 (757 of 907; 83.5%). New participants submitted 124 of 977 (12.7%) surveys. The median laboratory accession rate was 14,788 cases with 211 HER2 tests performed annually. Testing was validated with fluorescence in situ hybridization in 49.1% (443 of 902) of the laboratories; 26.3% (224 of 853) of the laboratories used another IHC assay. The median number of cases to validate fluorescence in situ hybridization (n = 40) and IHC (n = 27) was similar to those in 2008. Ninety-five percent concordance with fluorescence in situ hybridization was achieved by 76.5% (254 of 332) of laboratories for IHC(-) findings and 70.4% (233 of 331) for IHC(+) cases. Ninety-five percent concordance with another IHC assay was achieved by 71.1% (118 of 168) of the laboratories for negative findings and 69.6% (112 of 161) of the laboratories for positive cases. The proportion of laboratories interpreting HER2 IHC using ASCO/CAP guidelines (86.6% [798 of 921] in 2011; 83.8% [605 of 722] in 2008) remains similar.
  
  
  CONCLUSIONS
  Although fixation time improvements have been made, assay validation deficiencies still exist. The results of this survey were shared within the CAP, including the Laboratory Accreditation Program and the ASCO/CAP panel revising the HER2 guidelines published in October 2013. The Laboratory Accreditation Program checklist was changed to strengthen HER2 validation practices.
authors: From the Department of Anatomic Pathology, Cleveland Clinic foundation, Cleveland, Ohio (Dr Dyhdalo); the Department of Pathology, St Jude Medical Center, Fullerton, California (Dr Fitzgibbons); the Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts (Dr Goldsmith); the Department of Biostatistics, College of American Pathologists, Northfield, Illinois (Ms Souers); and the Department of Pathology, Mayo Clinic Florida, Jacksonville (Dr Nakhleh).
authors: Kathryn S
authors: KS
authors: Dyhdalo
authors: Patrick L
authors: PL
authors: Fitzgibbons
authors: Jeffery D
authors: JD
authors: Goldsmith
authors: Rhona J
authors: RJ
authors: Souers
authors: Raouf E
authors: RE
authors: Nakhleh
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D003625:Data Collection; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000592:standards; D017404:In Situ Hybridization, Fluorescence / Q000592:standards; D007753:Laboratories / Q000592:standards; D010338:Pathology, Clinical / Q000592:standards*; D017410:Practice Guidelines as Topic / Q000592:standards*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D012955:Societies, Medical; D014481:United States
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human