title: High inter-observer agreement in immunohistochemical evaluation of HER-2/neu expression in breast cancer: a multicentre GEFPICS study.
abstract: The accurate determination of HER-2 in invasive breast cancer has become a critical issue, particularly in the context of the results of recent trastuzumab (Herceptin((R))) adjuvant trials. This multicentre study evaluated inter-observer reproducibility in interpretation of HER-2 immunostains performed in different laboratories according to their in-house technique. A total of 74 HER-2 immunostains were evaluated by 16 pathologists and by a central review committee. As determined by central review, the HER-2 score was 0 in 33 cases (44%), 1+ in 10 cases (13%), 2+ in 9 cases (12%) and 3+ in 23 cases (31%). The overall kappa value was good (kappa=0.75). Agreement was excellent for the 0/1+ group (kappa=0.85) and for the 3+ group (kappa=0.82). As expected, the score 2+ group showed poor agreement (kappa=0.38). A quality assurance process showed that ring studies and adherence to national guidelines greatly improve inter-observer reproducibility.
authors.affiliation: Department of Pathology, Institut Claudius Regaud, 20-24 rue du pont Saint Pierre, 31052 Toulouse Cedex, France. lacroix.magali@claudiusregaud.fr <lacroix.magali@claudiusregaud.fr>
authors.forename: Magali
authors.initials: M
authors.lastname: Lacroix-Triki
authors.forename: Simone
authors.initials: S
authors.lastname: Mathoulin-Pelissier
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Ghnassia
authors.forename: Gaetan
authors.initials: G
authors.lastname: Macgrogan
authors.forename: Anne
authors.initials: A
authors.lastname: Vincent-Salomon
authors.forename: Véronique
authors.initials: V
authors.lastname: Brouste
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Mathieu
authors.forename: Pascal
authors.initials: P
authors.lastname: Roger
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bibeau
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Jacquemier
authors.forename: Frédérique
authors.initials: F
authors.lastname: Penault-Llorca
authors.forename: Laurent
authors.initials: L
authors.lastname: Arnould
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000592:standards; D008875:Middle Aged; D015588:Observer Variation; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases