Tumors, which overexpress HER2, are most suitable for treatment with Herceptin. HER2 overexpression can be detected at the protein level using immunohistochemistry (IHC) or at the DNA level using ISH.

Abbott's (Abbott Park, IL, USA) PathVysion FISH assay is the gold standard in situ hybridization (ISH) test for diagnosing the response of patients to Herceptin. Leica Microsystems (Wetzlar, Germany) will develop an automated version of this test to be performed on its BOND system using a standard protocol. Automation of the test on the Leica BOND system will enable pathology laboratories to run this diagnostic test more efficiently.

The PathVysion HER-2 DNA Probe Kit (PathVysion Kit), which is U.S. Food and Drug Administration (FDA; Silver Spring, MD, USA) approved, is designed to detect amplification of the HER-2/neu gene via fluorescence in situ hybridization (FISH) in formalin-fixed, paraffin-embedded human breast cancer tissue specimens.

The PathVysion Kit is not intended for use to screen for or diagnose breast cancer. It is intended to be used as an adjunct to other prognostic factors currently used to predict disease-free and overall survival in stage II, node-positive breast cancer patients.

Related Links:
Abbott's
Leica Microsystems