Indian Journal of Cancer
Medknow Publications on behalf of Indian Cancer Society
Vol. 41, No. 4, 2004, pp. 152-158
Bioline Code: cn04029
Full paper language: English
Document type: Research Article
Document available free of charge
Indian Journal of Cancer, Vol. 41, No. 4, 2004, pp. 152-158
© Copyright 2004 Indian Journal of Cancer.
FISH for HER-2/neu in breast cancer: Standardization makes the difference!|
Gokhale Sumita, Gatalica Zoran, Mohammad Amin, Rampy AI, Velagaleti Gopalrao VN
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.
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.
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%).
Based on these results, we consider FISH to be the gold standard for detecting HER-2/neu status in breast cancer.
Breast cancer, HER-2/neu, Amplification, IHC, FISH, DCIS, Pathvysion, Validation
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