HER-2/neu detection in fine-needle aspirates of breast cancer: fluorescence in situ hybridization and immunocytochemical analysis

Am J Clin Pathol. 2004 Aug;122(2):246-55. doi: 10.1309/N82C-TQ1J-0XEV-EFQB.

Abstract

We evaluated HER-2 receptor status by immunocytochemical and immunohistochemical analyses and fluorescence in situ hybridization (FISH) in 51 fine-needle aspiration (FNA) specimens together with the corresponding formalin-fixed, paraffin-embedded (FFPE) tissue samples obtained from surgically resected breast cancers. Three fixation methods were compared: ethanol, formalin, and CytoLyt-ThinPrep (Cytyc, Boxborough, MA). HER-2 was overexpressed and amplified in 8 (16%) of 51 FFPE specimens. Of the 8 cases, gene amplification was observed in 8 FNA specimens (100%) and overexpression in 2 (25%) ethanol-, 4 (50%) CytoLyt-, and 5 (63%) formalin-fixed FNA specimens. Strong pairwise kappa association between FISH results performed on FNA specimens and FFPE tissue samples (ethanol fixation, kappa = 0.848; ThinPrep, kappa = 0.918) and moderate (ThinPrep, kappa = 0.692; formalin fixation, kappa = 0.667) to poor (ethanol, kappa = 0.300) pairwise kappa agreement between tissue immunohistochemical and FNA immunocytochemical results was demonstrated. We conclude that HER-2 protein expression on cytologic preparations was insufficiently reliable for clinical use, whereas HER-2 gene amplification determined by FISH demonstrated strong and consistent correlation with HER-2 status of FFPE tissue samples.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / analysis*
  • Biopsy, Fine-Needle
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Carcinoma, Ductal, Breast / metabolism
  • Carcinoma, Ductal, Breast / pathology
  • Cytodiagnosis / methods
  • Ethanol
  • Female
  • Formaldehyde
  • Gene Amplification
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Middle Aged
  • Receptor, ErbB-2 / genetics
  • Receptor, ErbB-2 / metabolism*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tissue Fixation / methods

Substances

  • Biomarkers, Tumor
  • Formaldehyde
  • Ethanol
  • Receptor, ErbB-2