title: Human epidermal growth factor receptor-2 gene amplification in gastric cancer using tissue microarray technology.
abstract: OBJECTIVE
  To assess human epidermal growth factor receptor-2 (HER2)-status in gastric cancer and matched lymph node metastases by immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH).
  
  
  METHODS
  120 cases of primary gastric carcinomas and 45 matched lymph node metastases from patients with full clinicopathological features were mounted onto multiple-punch and single-punch tissue microarrays, respectively, and examined for HER2 overexpression and gene amplification by IHC and CISH.
  
  
  RESULTS
  Twenty-four tumors (20%) expressed HER2 immunohistochemically. An IHC score of ≥ 2+ was observed in 20 tumors (16.6%). HER2 amplification was detected by CISH in 19 tumors (15.8%) and in their matched lymph node metastases. A high concordance rate was found between HER2 positivity (as detected by IHC) and HER2 gene amplification (as detected by CISH), since 19 of the 20 IHC positive cases were amplified (95%). All amplified cases had 2+ or 3+ IHC results. Amplification was associated with intestinal phenotype (P < 0.05). No association with grading, staging or survival was found.
  
  
  CONCLUSIONS
  In gastric cancer, HER2 amplification is the main mechanism for HER2 protein overexpression and is preserved in lymph node metastases.
authors.affiliation: 3rd Department of Surgery, Attikon University Hospital, University of Athens, Rimini 1, 12464 Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Tsapralis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Panayiotides
authors.forename: George
authors.initials: G
authors.lastname: Peros
authors.forename: Theodore
authors.initials: T
authors.lastname: Liakakos
authors.forename: Eva
authors.initials: E
authors.lastname: Karamitopoulou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005784:Gene Amplification; D018734:Genes, erbB-2; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D046228:Microarray Analysis / Q000379:methods*; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases