Abstract
Accurate assessment of Her-2/neu (erb-b2) status in breast carcinoma is essential for therapy planning. Clinical assays are targeted at protein overexpression (immunohistochemical analysis) or gene amplification (fluorescence in situ hybridization [FISH]). Cases with aberrant FISH signal patterns are problematic and may lead to underreporting of Her-2/neu amplification. We performed FISH with additional chromosome 17 probes, SMS (Smith-Magenis syndrome critical region) and RARA (retinoic acid receptor), on 7 cases with unusual Her-2/CEP17 (chromosome 17 centromere control probe) results to assess whether different measurements of chromosome 17 copy number might clarify the Her-2/neu amplicon status. Although the Her-2/CEP17 ratio scores were within normal range (<2.0), the Her-2/SMS or Her-2/RARA ratio revealed amplification of Her-2/neu in 5 of 7 cases. Immunohistochemical analysis demonstrated Her-2/neu protein overexpression in the same 5 cases only. We describe novel application of SMS/RARA FISH probes for assessing cases with complex Her-2/CEP17 FISH patterns. Such additional data, correlated with immunohistochemical analysis, may help guide therapy in patients with breast carcinoma.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 709-716 |
| Number of pages | 8 |
| Journal | American journal of clinical pathology |
| Volume | 126 |
| Issue number | 5 |
| DOIs | |
| State | Published - Nov 2006 |
Keywords
- Breast carcinoma
- CEP17
- FISH
- Fluorescence in situ hybridization
- Her-2/neu
- Immunohistochemistry
- RARA
- Retinoic acid receptor
- Smith-Magenis syndrome
- erb-b2
ASJC Scopus subject areas
- Pathology and Forensic Medicine