HER-2/neu detection in fine-needle aspirates of breast cancer: fluorescence in situ hybridization and immunocytochemical analysis.
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.
Beatty
Barbara G
BG
Department of Pathology, University of Vermont College of Medicine, Burlington 05405-0068, USA.
Bryant
Ronald
R
Wang
Weichen
W
Ashikaga
Takamaru
T
Gibson
Pamela C
PC
Leiman
Gladwyn
G
Weaver
Donald L
DL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D044963:Biopsy, Fine-Needle; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology; D003581:Cytodiagnosis / Q000379:methods; D000431:Ethanol; D005260:Female; D005557:Formaldehyde; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016707:Tissue Fixation / Q000379:methods
D014408:Biomarkers, Tumor; D000431:Ethanol; D005557:Formaldehyde; D018719:Erb-b2 Receptor Tyrosine Kinases