title: Efficacy of primed in situ labelling in determination of HER-2 gene amplification and CEN-17 status in breast cancer tissue.
abstract: Considerable attention has been given to the accuracy of HER-2 testing and the correlation between the results of different testing methods. This interest reflects the growing importance of HER-2 status in the management of patients with breast cancer. In this study the detection of HER-2 gene and centromere 17 status was evaluated using dual-colour primed in situ labelling (PRINS) in comparison with fluorescence in situ hybridization (FISH). These two methods were evaluated on a series of 27 formalin fixed paraffin embedded breast carcinoma tumours, previously tested for protein overexpression by HercepTest (grouped into Hercep 1+/0, 2+ and 3+). HER-2 gene amplification (ratio ≥ 2.2) by PRINS was found in 3:3, 6:21 and 0:3 in IHC 3+, 2+ and 1+/0 cases, respectively. Comparing FISH and IHC (immunohistochemistry), showed the same results as for PRINS and IHC. Chromosome 17 aneusomy was found in 10 of 21 IHC 2+ cases (47.6%), of which 1 (10%) showed hypodisomy (chromosome 17 copy number per cell ≤ 1.75), 7 (70%) showed low polysomy (chromosome 17 copy number per cell=2.26 - 3.75) and 2 (20%) showed high polysomy (chromosome 17 copy number per cell ≥ 3.76). The overall concordance of detection of HER-2 gene amplification by FISH and PRINS was 100% (27:27). Furthermore, both the level of HER-2 amplification and copy number of CEN17 analysis results correlated well between the two methods. In conclusion, PRINS is a reliable, reproducible technique and in our opinion can be used as an additional test to determine HER-2 status in breast tumours.
authors.affiliation: Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Salimi
authors.forename: Hossein
authors.initials: H
authors.lastname: Mozdarani
authors.forename: Keivan
authors.initials: K
authors.lastname: Majidzadeh-A
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018385:Centrosome; D002869:Chromosome Aberrations; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D005260:Female; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D017404:In Situ Hybridization, Fluorescence; D016612:Paraffin Embedding; D020401:Primed In Situ Labeling / Q000379:methods* / Q000706:statistics & numerical data; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases