title: Assessing HER2 amplification by IHC, FISH, and real-time polymerase chain reaction analysis (real-time PCR) following LCM in formalin-fixed paraffin embedded tissue from 40 women with ovarian cancer.
abstract: We compare HER2 receptor amplification analysis by immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and real-time polymerase chain reaction (real-time PCR) DNA copy-number assay following laser capture microdissection (LCM) in formalin-fixed paraffin embedded tissue from 40 women with verified ovarian cancer. We speculate that LCM should result in a more accurate assessment of HER2 amplification in our real-time PCR assay compared with IHC and FISH. HER2 overexpression measured by IHC, FISH, or real-time PCR was found in 5.0%, 5.0%, and 22.5%, respectively. HER2 negative results measured by IHC, FISH, or real-time PCR were found in 95%, 92.5%, and 60.0%, respectively. Analysis failed for IHC, FISH, or real-time PCR in 0%, 2.5%, or 17.5% of cases. Concordance between IHC and FISH, IHC and real-time PCR, or FISH and real-time PCR were 89.7%, 72.7%, or 78.1%, respectively. Only few ovarian cancer patients were HER2 overexpressed measured by IHC or FISH and thus could be eligible for antibody-based therapy with trastuzumab (Herceptin). Interestingly, we find an increased number of HER2 positive patients by real-time PCR analysis on microdissected cancer cells, suggesting a number of HER2 positive patients not detected by current methods. Thus, the concept of quantitative measurement of HER2 on microdissected cancer cells should be explored further.
authors.affiliation: Department of Clinical Biochemistry, Hillerød Hospital University of Copenhagen, 3400 Hillerød, Denmark. Thill@noh.regionh.dk
authors.forename: Thore
authors.initials: T
authors.lastname: Hillig
authors.forename: Jørgen
authors.initials: J
authors.lastname: Thode
authors.forename: Marie F
authors.initials: MF
authors.lastname: Breinholt
authors.forename: Maria-Benedicte
authors.initials: MB
authors.lastname: Franzmann
authors.forename: Carsten
authors.initials: C
authors.lastname: Pedersen
authors.forename: Flemming
authors.initials: F
authors.lastname: Lund
authors.forename: Henrik
authors.initials: H
authors.lastname: Mygind
authors.forename: György
authors.initials: G
authors.lastname: Sölétormos
authors.forename: Martin
authors.initials: M
authors.lastname: Rudnicki
mesh_terms: D061067:Antibodies, Monoclonal, Humanized; D005260:Female; D005784:Gene Amplification; D018628:Gene Dosage; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D061346:Laser Capture Microdissection; D010051:Ovarian Neoplasms / Q000235:genetics*; D016612:Paraffin Embedding; D060888:Real-Time Polymerase Chain Reaction; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics*; D000068878:Trastuzumab; D014407:Tumor Cells, Cultured
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human