| ORIGINAL ARTICLE
|Year : 2004 | Volume
| Issue : 4 | Page : 152-158
FISH for HER-2/neu in breast cancer: Standardization makes the difference!
Sumita Gokhale1, Zoran Gatalica1, Amin Mohammad1, AI Rampy1, VN Velagaleti Gopalrao2
1 Department of Pathology, University of Texas Medicine Branch, Glveston, TX, USA
2 Department of Pediatrics, University of Texas Medicine Branch, Glveston, TX, USA
CONTEXT : Overexpression of HER-2/neu oncogene in breast cancer patients is correlated with disease free survival (DFS) and overall survival (OS). The most commonly used methods for the detection of HER-2/neu status are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). However, therse is a lot of controversy with regard to the best method. Most of the FISH studies chose arbitrary cut-off levels for positive results (10%) and had no validation. AIM : In order to address these issues, we designed a pilot study of 38 samples with known IHC status representing all 4 categories. SETTINGS AND DESIGN : FISH was performed using Vysis Pathvysion™ probe. For validation, 5 cases of reduction mammoplasty were analyzed using same protocols. RESULTS : Our results showed significant discordance between FISH and IHC. The rate of discordance was much higher in the 0, 1+, and 2+ categories compared to published literature. This could be due to the lower cut-off rates for positive amplification established by validation in our study (5.7% vs 10%). Our analysis showed that FISH positive and IHC negative patients have a poor prognosis in terms of DFS and OS compared to FISH negative and IHC negative patients. Further, our results also showed that IHC in comparison to FISH has a comparable specificity (98%), but has a very low sensitivity (46%). CONCLUSION : Based on these results, we consider FISH to be the gold standard for detecting HER-2/neu status in breast cancer.
V N Velagaleti Gopalrao
Department of Pediatrics, University of Texas Medicine Branch, Glveston, TX
Source of Support: None, Conflict of Interest: None
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