title: Inter-observer agreement in reporting HER 2 Neu protein over expression by immunohistochemistry.
abstract: BACKGROUND
  HER 2 Neu protein overexpression and its detection by immunohistochemistry (IHC) has become quiet critical because of its relevance in regards to Herceptin treatment. This peer review was done at a tertiary care center, which aimed at determining the inter-observer variation among five pathologists and evaluating the degree of agreement between them.
  
  
  OBJECTIVE
  The aim of our study was to determine the reproducibility of HER 2 Neu system of reporting in breast cancer cases and determine inter-observer variability among five pathologists at a tertiary care center. To compare the results with similar studies done at other centers.
  
  
  METHODS
  Retrospective descriptive study.
  
  
  METHODS
  Hematoxylin and Eosin (H and E) and IHC stained slides of 104 cases of carcinoma breast, on which HER 2 Neu status had been reported were reviewed. The time period for selection was from January 2010 to December 2011 (2 year period). Five pathologists reviewed the H and E and IHC slides independently and scored the results on a specially designed work sheet. Kappa values for inter-observer variation and Cornbach's alpha for internal consistency were calculated.
  
  
  METHODS
  SPSS 20.0 (IBM). not known.
  
  
  RESULTS
  Complete agreement was seen between all five pathologists in 70 cases (70/104) = 67%. Agreement between four pathologists was seen in 78 cases (78/104) = 75%. Agreement between three pathologists was seen in 92 cases (92/104) = 88%. The global value for kappa co efficient for agreement between two pathologists was 0.706 and Cornbach alpha for internal consistency of reporting in the department was 0.987. CONCLUSION/KEY MESSAGES: Our departmental peer review indicated that there is good inter-observer concordance (agreement between two pathologists) and there is strong overall internal consistency of reporting for HER 2 Neu reporting by IHC. Our results are comparable to International reported data of similar studies.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Al Haddabi
authors.affiliation: Department of Pathology, Sultan Qaboos University, Muscat, Oman.
authors.forename: Asim
authors.initials: A
authors.lastname: Qureshi
authors.forename: Anna
authors.initials: A
authors.lastname: Saparamadu
authors.forename: Aisha
authors.initials: A
authors.lastname: Al Hamdani
authors.forename: Marwa
authors.initials: M
authors.lastname: Al Riyami
authors.forename: Shyam
authors.initials: S
authors.lastname: Ganguly
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D015870:Gene Expression; D006302:Health Services Research; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods* / Q000592:standards; D015588:Observer Variation; D010336:Pathology / Q000379:methods* / Q000592:standards; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D012189:Retrospective Studies; D062606:Tertiary Care Centers
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases