title: Utility of cytopathological specimens and an automated image analysis for the evaluation of HER2 status and intratumor heterogeneity in breast carcinoma.
abstract: OBJECTIVE
  Although updated HER2 testing guidelines have been improved by a collaboration between the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) in 2013, HER2 evaluation is still problematic because of issues involving CEP17 polysomy, heterogeneity, and HER2 score 2+ cases. The aim of this retrospective study was to evaluate the relationship between HER2 gene heterogeneity, or so called CEP17 polysomy, using breast carcinoma cells sampled by scraping and the IHC score graded by automated image analysis using whole slide image.
  
  
  METHODS
  We randomly selected 23 breast carcinoma cases with a HER2 score 0, 24 cases with a HER2 score 1+, 24 cases with HER2 score 2+, and 23 cases with HER2 score 3+ from the records of patients with breast cancer at Hiroshima University Hospital. We compared the results of fluorescent in situ hybridization (FISH) using formalin-fixed, paraffin-embedded (FFPE) tissues and cytological samples and compared the HER2 score calculated using an automated image analysis using wholly scanned slide images and visual counting.
  
  
  RESULTS
  We successfully performed the FISH assay in 78 of 94 cases (83%) using FFPE tissues and in all 94 (100%) cases using cytological samples. Frequency of both HER2 amplification and CEP17 polysomy was higher when cytological samples were used than when FFPE tissue was used. Frequency of HER2 heterogeneity using cytological samples was higher that than using FFPE tissue, except for the IHC score 3+ cases.
  
  
  CONCLUSIONS
  When assessment of HER2 status based on FISH using FFPE tissue cannot be accomplished, FISH using cytological samples should be considered. When intensity of HER2 is heterogeneous in the tumor tissue, particularly in cases regarded as score 2+, they should be evaluated by automated image analysis using the whole slide image.
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan. Electronic address: arihiro@hiroshima-u.ac.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Arihiro
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Miyo
authors.initials: M
authors.lastname: Oda
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Katsunari
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Yuna
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Marubashi
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Katsunari
authors.initials: K
authors.lastname: Ishida
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Takai
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Taoka
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Shiroma
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017404:In Situ Hybridization, Fluorescence; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: Breast cancer; Cytological sample; FISH; HER2; Image analysis; Whole slide image