title: HER2 gene amplification in breast cancer: a rogues' gallery of challenging diagnostic cases: UKNEQAS interpretation guidelines and research recommendations.
abstract: International and national guidelines highlight the importance of accuracy, reproducibility, and quality control of in situ hybridization (ISH) methods for testing breast carcinomas. However, few guidelines cover the reporting of ISH cases with "unusual" signal patterns, including, eg, heterogeneity and loss of chromosome enumeration probe or gene signals. These cases are, in fact, relatively frequent, and there is a need for developing evidence- or consensus-based reporting guidelines to ensure consistency of treatment. Following an audit of cases from a single center (including >1,700 cases) we show that approximately 10% of ISH results reflect unusual signal patterns. We illustrate the most common of these patterns and provide reporting guidelines for diagnosticians and recommendations for future research. Our goal is to ensure that in the future such "rogues" are reported in a consistent manner that, ultimately, will be supported by molecular and biochemical evidence.
authors.affiliation: Cellular Pathology, Birmingham Heartlands Hospital, England, UK.
authors.forename: Jane
authors.initials: J
authors.lastname: Starczynski
authors.forename: Neil
authors.initials: N
authors.lastname: Atkey
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Connelly
authors.forename: Tony
authors.initials: T
authors.lastname: O'Grady
authors.forename: Fiona M
authors.initials: FM
authors.lastname: Campbell
authors.forename: Silvana
authors.initials: S
authors.lastname: di Palma
authors.forename: Peter
authors.initials: P
authors.lastname: Wencyk
authors.forename: Bharat
authors.initials: B
authors.lastname: Jasani
authors.forename: Michael
authors.initials: M
authors.lastname: Gandy
authors.forename: J M S
authors.initials: JM
authors.lastname: Bartlett
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D005260:Female; D005784:Gene Amplification; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D011786:Quality Control; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D015203:Reproducibility of Results
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases