Her-2/neu overexpression due to polysomy 17 in breast cancer: molecular testing to guide therapeutic options.

Background: Fluorescent in situ hybridization (FISH) equivocal results for Her-2/neu still pose a diagnostic dilemma in oncology practice. In this study, we evaluate if Her-2/neu mRNA expression is an alternative to FISH for detecting Her-2/neu positivity.

Patients And Methods: Archival paraffin blocks of 54 breast cancer patients were analyzed for Her-2/neu status using immunohistochemistry (IHC), FISH, and Her-2/neu gene expression using mRNA.