High inter-observer agreement in immunohistochemical evaluation of HER-2/neu expression in breast cancer: a multicentre GEFPICS study.
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.
Lacroix-Triki
Magali
M
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>
Mathoulin-Pelissier
Simone
S
Ghnassia
Jean-Pierre
JP
Macgrogan
Gaetan
G
Vincent-Salomon
Anne
A
Brouste
Véronique
V
Mathieu
Marie-Christine
MC
Roger
Pascal
P
Bibeau
Frédéric
F
Jacquemier
Jocelyne
J
Penault-Llorca
Frédérique
F
Arnould
Laurent
L
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*
D018719:Erb-b2 Receptor Tyrosine Kinases