title: Chromogenic in situ hybridization (CISH) to detect HER2 gene amplification in breast and gastric cancer: comparison with immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH).
abstract: The chromogenic in situ hybridization (CISH) assay, designed to detect the amplification of the HER2 gene in formalin-fixed, paraffin-embedded (FFPE) breast cancer (BC) and gastric cancer (GC) tissue specimens, was evaluated in 125 FFPE BC cases and 198 FFPE GC cases for which the HER2 status had been predetermined using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). In the 125 BC cases and the 198 gastric cases, we found a very good concordance (98.4% and 99.0%, respectively) between CISH and FISH. In particular, we evaluated the polysomy cases, as these cases often have ambiguous treatment options in clinical practice. The polysomy of chromosome 17 was defined as the presence of three or more CEP17 signals in at least 10% of the tumor cells. In the 50 BC cases and 54 GC cases displaying chromosome 17 polysomy, the concordance between FISH and CISH was 98.0% and 98.1%, respectively. These results indicate that CISH could provide an accurate and practical alternative to FISH for the clinical diagnosis of HER2 gene amplification in FFPE BC and FFPE GC samples.
authors.affiliation: Department of Tumor Pathology, Hamamatsu University School of Medicine, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kiyose
authors.forename: Hisaki
authors.initials: H
authors.lastname: Igarashi
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Nagura
authors.forename: Takaharu
authors.initials: T
authors.lastname: Kamo
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kawane
authors.forename: Hiroki
authors.initials: H
authors.lastname: Mori
authors.forename: Takachika
authors.initials: T
authors.lastname: Ozawa
authors.forename: Matsuyoshi
authors.initials: M
authors.lastname: Maeda
authors.forename: Keisuke
authors.initials: K
authors.lastname: Konno
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hoshino
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Konno
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ogura
authors.forename: Kazuya
authors.initials: K
authors.lastname: Shinmura
authors.forename: Naohiko
authors.initials: N
authors.lastname: Hattori
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Sugimura
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005557:Formaldehyde; D005784:Gene Amplification; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D016612:Paraffin Embedding; D011237:Predictive Value of Tests; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D015203:Reproducibility of Results; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism; D046888:Tissue Array Analysis; D016707:Tissue Fixation
chemical_list: D014408:Biomarkers, Tumor; D005557:Formaldehyde; D018719:Erb-b2 Receptor Tyrosine Kinases