title: Quantitative immunohistochemical evaluation of HER2/neu expression with HercepTestTM in breast carcinoma by image analysis.
abstract: HercepTestTM (DAKO A/S, Glostrup, Denmark) is an immunohistochemical assay that detects HER2/neu gene products, and evaluates the overexpression status of the HER2/neu protein in determining eligibility for the Trastuzumab (HerceptinR, Genentech, San Francisco, CA, USA) therapy. However, practically, interobserver variability of the HER2/neu interpretation of the immunostained results has caused marked disagreement with regard to the intensity of tumor staining. In this study, we quantitated HER2/neu expression by image analysis, and applied this analyzing system to help to minimize interobserver variability of the interpretation of the HercepTestTM. All the immunostained results were scored semiquantitatively on a range of 0 to 3+ in accordance with the criteria described as per the manufacturer's instructions, and quantitatively evaluated using an image analyzing system with image processing software. Among the 92 cases, 15 were scored as 3+, six were 2+, and 32 were 1+ under intraobservers agreement. When the cases were quantitated, a high correlation was shown between the signal area extracted by image analysis and the corresponding score of staining intensity with the HercepTestTM. By converting the quantitatively extracted data into a scoring system based upon the criteria, the outcome demonstrated a strong concordance with the scoring data obtained from immunostaining. The results indicated that a quantitative scoring system performed by simple image analysis may provide to improve interobserver agreement of the interpretation of the HercepTest TM in clinical practice.
authors.affiliation: Department of Immunohistochemistry, DAKO Japan Co. Ltd, 18 Kakkyoyama, Nishinitoin-higashiru, Shijo-dori, Simogyo, Kyoto 600-8493, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hatanaka
authors.forename: K
authors.initials: K
authors.lastname: Hashizume
authors.forename: Y
authors.initials: Y
authors.lastname: Kamihara
authors.forename: H
authors.initials: H
authors.lastname: Itoh
authors.forename: H
authors.initials: H
authors.lastname: Tsuda
authors.forename: R Y
authors.initials: RY
authors.lastname: Osamura
authors.forename: Y
authors.initials: Y
authors.lastname: Tani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000737:chemistry* / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007150:Immunohistochemistry / Q000379:methods*; D008875:Middle Aged; D015588:Observer Variation; D011933:Reagent Kits, Diagnostic; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: D011933:Reagent Kits, Diagnostic; D018719:Erb-b2 Receptor Tyrosine Kinases