title: Dual-color silver-enhanced in situ hybridization for assessing HER2 gene amplification in breast cancer.
abstract: Amplification of the human epidermal growth factor receptor 2 (HER2) gene occurs in 20-25% of breast cancers, and is recognized as a prognostic and predictive marker. HER2 gene amplification, evaluated as a change in protein expression or gene copy number, can be identified by a number of methods. Fluorescence in situ hybridization (FISH) is considered the gold standard for HER2 gene copy number determination; however, a number of impediments prevent its wider use in a clinical setting. The aims of our study were to compare dual-color silver-enhanced in situ hybridization (SISH) with single-color SISH and FISH on formalin-fixed, paraffin-embedded sections, and to validate its use as a routine method for assessing HER2 status in breast cancers. A total of 146 invasive breast carcinoma cases were assessed for HER2 gene amplification by FISH and dual-color SISH. Dual-color SISH and FISH results exhibited a concordance rate of 97% (κ=0.912). A comparison of the single-color SISH method with dual-color SISH showed that 142 of 146 cases were in agreement (97%, κ=0.930). Our results showed that dual-color SISH is a viable alternative to FISH that offers a number of advantages in a clinical setting.
authors.affiliation: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Young Wha
authors.initials: YW
authors.lastname: Koh
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Lee
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Jun
authors.initials: J
authors.lastname: Kang
authors.forename: Gyungyub
authors.initials: G
authors.lastname: Gong
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005784:Gene Amplification; D018734:Genes, erbB-2; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods*; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D015203:Reproducibility of Results; D016622:Silver Staining
chemical_list: D014408:Biomarkers, Tumor