erb-b2 amplification by fluorescence in situ hybridization in breast cancer specimens read as 2+ in immunohistochemical analysis

Chieh Lan, Jacqueline Ming Liu, Tsang Wu Liu, Der Hung Hsu, Shuching Liang, Jim Ray Chen, Jacqueline Whang Peng

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We conducted this study to ascertain the prevalence of erb-b2 gene amplification in breast cancer specimens read as 2+ in immunohistochemical analysis. Slides from patients with metastatic or recurrent breast cancer were eligible for fluorescent in situ hybridization (FISH) study if they were read as 2+ immunohistochemically for erb-b2 by a certified pathologist. The PathVysion kit (Vysis, Downers Grove, IL) was used for FISH studies. Amplification of the erb-b2 gene was defined as an erb-b2/CEP17 (chromosome 17 centromere) ratio of 2 or more in 30 tumor cells counted. From May 2003 to June 2004, 221 slides were submitted from 24 hospitals around the island. Of 216 successful hybridizations, 96 (44.4%) were determined to be erb-b2 amplified. In addition, the topoisomerase IIα gene was coamplified in 11 (21%) of 53 and deleted in 8 (15%) of 53 erb-b2 amplified cases. The erb-b2 gene amplification rate was very high in cases determined to be 2+ by immunohistochemical analysis; therefore, determination of erb-b2 status by FISH in cases scored 2+ immunohistochemically is strongly recommended.

Original languageEnglish
Pages (from-to)97-102
Number of pages6
JournalAmerican Journal of Clinical Pathology
Issue number1
Publication statusPublished - Jul 1 2005
Externally publishedYes



  • Breast cancer
  • erb-b2
  • Fluorescence in situ hybridization
  • Immunohistochemistry
  • Topoisomerase 2α

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

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