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Dual color chromogenic in situ hybridization for determination of HER2 status in breast cancer: a large comparative study to current state of the art fluorescence in situ hybridization

Jens Mollerup*, Ulla Henriksen, Sven Müller and Andreas Schønau

Author Affiliations

Dako Denmark A/S, Produktionsvej 42, DK-2600 Glostrup, Denmark

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BMC Clinical Pathology 2012, 12:3  doi:10.1186/1472-6890-12-3

Published: 14 February 2012



Chromogenic in situ hybridization (CISH) is fast becoming a well established technique for easy and sensitive determination of HER2 gene status in breast cancer. However, for the chromogenic method to achieve status as a safe and reliable technique, the method needs to be validated against already known and validated FISH techniques.


Here it is reported from a comparative study where HER2 gene status obtained by HER2 CISH pharmDx™ Kit was compared to HER2 gene status obtained by the FDA approved HER2 FISH pharmDx™ Kit and the PathVysion HER-2 DNA probe Kit. The study included 365 formalin fixed and paraffin-embedded invasive breast cancer tissue specimens collected consecutively at a US reference laboratory.


The data obtained revealed an overall HER2 status concordance of approximately 98% for comparisons of HER2 CISH pharmDx™ Kit to both HER2 FISH pharmDx™ Kit and PathVysion HER-2 DNA Probe Kit.


The concordance between results obtained using the recently FDA approved HER2 CISH pharmDx™ Kit with previously FDA approved FISH techniques for HER2 gene status determination indicate that the HER2 CISH pharmDx™ Kit is a reliable chromogenic alternative to fluorescence-based methods.