Significance of accurate human epidermal growth factor receptor-2 (HER2) evaluation as a new biomarker in gastric cancer

Anticancer Res. 2014 Aug;34(8):4207-12.

Abstract

Background: HER2 testing in gastric cancer differs from testing in breast cancer because of inherent differences in tumor biology; gastric cancer more frequently shows HER2 heterogeneity and incomplete membrane staining. The aim of the present study was to evaluate the frequency and accuracy of detection of HER2 expression by application of standard criteria in Japanese patients with gastric cancer.

Material and methods: A total of 198 tumor specimens were assessed for HER2 expression by immunohistochemistry (IHC) using the antibodies HercepTest™ and 4B5. Both hand-operated and automated IHC were performed.

Results: HER2 expression differed according to the IHC method and antibodies used. HER2 IHC3+ tumors were identified in 21 (10%) and 7 (3.5%) cases by hand-operated and automated IHC, respectively.

Conclusion: Among patients with gastric cancer, FISH may be performed in cases of IHC1+ by automated IHC. Further research is required to clarify the relevance of HER2 staining and scoring for the clinical response to HER2-targeted therapy.

Keywords: Human epidermal growth factor receptor-2 (HER2); gastric cancer; immunohistochemistry (IHC).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers, Tumor / analysis*
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Receptor, ErbB-2 / analysis*
  • Receptor, ErbB-2 / antagonists & inhibitors
  • Stomach Neoplasms / chemistry*
  • Stomach Neoplasms / pathology
  • Stomach Neoplasms / therapy

Substances

  • Biomarkers, Tumor
  • ERBB2 protein, human
  • Receptor, ErbB-2