erb-b2 amplification by fluorescence in situ hybridization in breast cancer specimens read as 2+ in immunohistochemical analysis.
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 IIa 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.
Lan
Chieh
C
Division of Cancer Research, National Health Research Institutes, Taipei, Taiwan.
Liu
Jacqueline Ming
JM
Liu
Tsang-Wu
TW
Hsu
Der-Hung
DH
Liang
Suching
S
Chen
Jim-Ray
JR
Peng
Jacqueline Whang
JW
D000951:Antigens, Neoplasm / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005784:Gene Amplification; D018734:Genes, erbB-2 / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D009362:Neoplasm Metastasis / Q000235:genetics / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000473:pathology; D011379:Prognosis; D012680:Sensitivity and Specificity; D013624:Taiwan
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D004250:DNA Topoisomerases, Type II