title: Usefulness and limitation of multiple endoscopic biopsy sampling for epidermal growth factor receptor and c-erbB-2 testing in patients with gastric adenocarcinoma.
abstract: BACKGROUND
  Our objective was to examine the utility of endoscopic biopsy specimens in judging the status of epidermal growth factor receptor (EGFR) and c-erbB-2 genes and proteins in the entire tumor.
  
  
  METHODS
  Endoscopic biopsy specimens and specimens of whole representative cut surfaces of corresponding surgically resected tumors were obtained from 14 patients with gastric carcinoma, and immunohistochemistry and fluorescence in situ hybridization were then performed to determine the protein expression and gene amplification profiles, respectively, of EGFR and c-erbB-2 in these biopsy and surgical specimens.
  
  
  RESULTS
  Among the eight endoscopic biopsy specimens obtained from three gastric carcinomas in which EGFR protein overexpression and gene amplification were judged to be positive in the corresponding surgically resected tissue specimens, EGFR overexpression was detected in three specimens (38%), but EGFR amplification was not detected (0%). Among the 19 endoscopic biopsy specimens obtained from five gastric carcinomas in which c-erbB-2 protein overexpression and gene amplification were judged to be positive in the corresponding surgically resected tissue specimens, c-erbB-2 overexpression and amplification (c-erbB-2/CEP17 ratio) were detected in 14 (74%) and 16 (84%) specimens, respectively. All three cases with EGFR overexpression and all five cases with c-erbB-2 overexpression showed intratumor heterogeneity with regard to their EGFR and c-erbB-2 status, respectively.
  
  
  CONCLUSIONS
  The c-erbB-2 status could be adequately assessed not only by examining surgically resected materials, but also by examining multiple endoscopic biopsy specimens. On the other hand, to assess the EGFR status accurately, the use of surgically resected samples appeared to be more reliable than the use of multiple endoscopic biopsy samples.
authors.affiliation: Department of Pathology II, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
authors.forename: Mikihiko
authors.initials: M
authors.lastname: Kimura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tsuda
authors.forename: Daisaku
authors.initials: D
authors.lastname: Morita
authors.forename: Eiji
authors.initials: E
authors.lastname: Shinto
authors.forename: Takao
authors.initials: T
authors.lastname: Tanimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Ichikura
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Mochizuki
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsubara
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D001706:Biopsy / Q000379:methods; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000235:genetics; D005743:Gastrectomy; D005773:Gastroscopy; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics; D013270:Stomach / Q000473:pathology*; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor; D066246:ErbB Receptors; D018719:Erb-b2 Receptor Tyrosine Kinases