Coexpression of EGFR and HER-2 in pancreatic ductal adenocarcinoma: a comparative study using immunohistochemistry correlated with gene amplification by fluorescencent in situ hybridization

Oncol Rep. 2007 Jul;18(1):151-5.


Pancreatic ductal adenocarcinoma (PDAC) is the major pancreatic tumor and carries an extremely poor prognosis. Coexpression of epidermal growth factor receptor (EGFR) and the HER-2 oncoprotein has been reported to be related to the invasion and an adverse clinical outcome of human pancreatic ductal adenocarcinomas. HER-2 amplification, as determined by fluorescent in situ hybridization (FISH) analysis, has been identified as a positive predictor of response to EGFR tyrosine kinase inhibitor treatment in some other cancers. The aim of this study was to investigate the coexpression rate and amplification status of HER-2 oncogene in EGFR positive pancreatic ductal adenocarcinoma (PDAC) by immunohistochemistry and FISH. Overexpression of EGFR (>or=2+) was seen in 65% (21/32) of the study cases. EGFR gene amplification was not detected in any of the 32 PDACs. Overexpression of HER-2 protein (>or=2+) was seen in 17% (5/28) of the study cases and in 24% (5/21) of EGFR positive cases. None of the EGFR negative tumors showed HER-2 overexpression or gene amplification. The HER-2 gene locus was amplified in 11% (3/28) of the study cases and in 14% (3/21) of EGFR positive PDACs. There was 60% concurrence between HER-2 gene amplification and HER-2 protein expression in this study. These results suggest that HER-2 is an important cooperating member of the EGFR signal pathway in a subset of PDAC.

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism*
  • Adenocarcinoma / pathology
  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma, Pancreatic Ductal / genetics
  • Carcinoma, Pancreatic Ductal / metabolism*
  • Carcinoma, Pancreatic Ductal / pathology
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • Female
  • Gene Amplification
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Immunoenzyme Techniques
  • In Situ Hybridization, Fluorescence
  • Male
  • Middle Aged
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Prognosis
  • Receptor, ErbB-2 / genetics
  • Receptor, ErbB-2 / metabolism*


  • ErbB Receptors
  • Receptor, ErbB-2