Fluorescence in situ hybridization and immunohistochemical assays for HER-2/neu status determination: application to node-negative breast cancer

Arch Pathol Lab Med. 2001 Jun;125(6):746-50. doi: 10.5858/2001-125-0746-FISHAI.


Background: HER-2/neu (ERBB2) gene amplification and/or overexpression is a major event in human breast tumorigenesis. HER-2/neu gene alterations have been the most frequently assessed prognostic factors during the last 10 years in breast cancer and have recently emerged as a management decision tool and a therapeutic target. There is still controversy over the best method to determine whether a tumor is HER-2/neu positive. Because of the increasing demand for HER-2/neu gene status determination in clinical practice, we compared HER-2/neu gene alterations at the DNA level (gene amplification) and the protein level (overexpression) in a panel of patients with lymph node-negative breast cancer who had received local radiotherapy alone, with no adjuvant therapy.

Methods: We tested 100 excised lymph node-negative breast tumors, using fluorescence in situ hybridization (FISH) with a biotinylated HER-2/neu DNA probe and immunohistochemical assays (IHC) with 2 different antibodies.

Results: The FISH frequency of HER-2/neu gene amplification was 15%, and the IHC frequency of overexpression was 21%.

Conclusion: Although HER-2/neu amplification by FISH and HER-2/neu overexpression by IHC correlated well in this panel of lymph node-negative breast carcinomas, there were a number of discordant cases, pointing to the important need for determining HER-2/neu alteration for the future management of HER-2/neu-based clinical applications.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • Female
  • Gene Amplification
  • Gene Expression
  • Genes, erbB-2*
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Lymphatic Metastasis
  • Middle Aged
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / metabolism
  • Neoplasm Recurrence, Local / pathology
  • Prognosis
  • Receptor, ErbB-2 / metabolism*


  • Receptor, ErbB-2