title: Impact of immunohistochemical markers, CK5/6 and E-cadherin on diagnostic agreement in non-invasive proliferative breast lesions.
abstract: OBJECTIVE
  To assess the impact of cytokeratin (CK) 5/6 and E-cadherin immunohistochemistry on diagnostic agreement of non-invasive proliferative breast lesions.
  
  
  RESULTS
  Twenty pathologists classified 105 cases of non-invasive proliferative breast lesions into 10 diagnostic categories. One haematoxylin and eosin (H&E) slide of each case was analysed on a first round and one H&E slide with corresponding CK5/6 and E-cadherin immunohistochemistry was analysed on a second round. Interobserver reproducibility for category-specific and management-specific lesions was measured on each round. CK5/6 and E-cadherin had little impact on diagnostic agreement, which remained moderate between the first and second rounds (overall kappa coefficients of 0.47 and 0.53, respectively, P = NS). Levels of agreement slightly improved for lesions with specific CK5/6 and E-cadherin immunoprofiles (usual ductal hyperplasia, atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ, non-high-grade ductal carcinoma in situ), but the differences observed were not statistically significant. However, diagnostic agreement improved when lesions were grouped according to their management category (overall kappa coefficients of 0.58 and 0.66 in the first and second rounds, respectively).
  
  
  CONCLUSIONS
  CK5/6 and E-cadherin immunohistochemistry has little impact on interobserver reproducibility for non-invasive breast lesions. Diagnostic agreement can, however, be improved by grouping lesions in management categories.
authors.affiliation: Department of Pathology, Institut Bergonié, Bordeaux, France. macgrogan@bergonie.org
authors.forename: G
authors.initials: G
authors.lastname: MacGrogan
authors.forename: L
authors.initials: L
authors.lastname: Arnould
authors.forename: I
authors.initials: I
authors.lastname: de Mascarel
authors.forename: A
authors.initials: A
authors.lastname: Vincent-Salomon
authors.forename: F
authors.initials: F
authors.lastname: Penault-Llorca
authors.forename: M
authors.initials: M
authors.lastname: Lacroix-Triki
authors.forename: F
authors.initials: F
authors.lastname: Bibeau
authors.forename: M C
authors.initials: MC
authors.lastname: Baranzelli
authors.forename: V
authors.initials: V
authors.lastname: Fridman
authors.forename: M
authors.initials: M
authors.lastname: Antoine
authors.forename: V
authors.initials: V
authors.lastname: Bécette
authors.forename: V
authors.initials: V
authors.lastname: Brouste
authors.forename: J
authors.initials: J
authors.lastname: Jacquemier
authors.forename: S
authors.initials: S
authors.lastname: Mathoulin-Pélissier
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis* / Q000276:immunology; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D015820:Cadherins / Q000032:analysis* / Q000276:immunology; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis* / Q000276:immunology
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; D007633:Keratins