Analysis of aneusomy level and HER-2 gene copy number and their effect on amplification rate in breast cancer specimens read as 2+ in immunohistochemical analysis.
Eur J Cancer
; 42(10): 1501-6, 2006 Jul.
Article
in En
| MEDLINE
| ID: mdl-16762541
ABSTRACT
Our aim was to determine the aneusomy level and the HER-2 gene copy numbers, by fluorescence in situ hybridization (FISH) and to analyze their impact on the amplification rate in breast carcinomas considered HER-2 weakly positive cases by immunohistochemistry. We evaluated 343 breast carcinomas using double colour FISH (LSI Her-2/neu gene and CEP 17). Monosomy and polysomy were demonstrated in 24.2% and 46.1% respectively and 101/343 (29.6%) of the specimens were amplified by FISH. A statistically significant difference was observed, when we compared the amplification percentage in polysomic and monosomic specimens (P<0.0001) and, among polysomic specimens, when tumours were compared with HER-2 gene signals number per cell between 3 and 10 and >10 respectively (P<0.0001). Logistic regression analysis showed that HER-2 signals >10 and polysomy absence were independently associated with amplification. Our results confirm that the majority of 2+ IHC cases express the HER-2 protein without gene amplification and highlight the effect of chromosome 17 aneusomy and the HER-2 gene copy number on amplification.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Breast Neoplasms
/
Chromosome Aberrations
/
Receptor, ErbB-2
/
Genes, erbB-2
Type of study:
Diagnostic_studies
Limits:
Humans
Language:
En
Journal:
Eur J Cancer
Year:
2006
Document type:
Article