The Her2 gene codes for a transmembrane growth factor receptor. Gene amplification and consequent overexpression of Her2 occurs in around 20% of women with breast cancer and is associated with an adverse prognosis. Trastuzumab (Herceptin® :Roche) is a chimeric antibody (95% human and 5% murine) developed against the Her2 protein. In HER2-positive metastatic disease
Trastuzumab alone has been shown to achieve a clinical response in around 35% of patients as first line treatment and significantly prolongs survival in combination with Paclitaxel and Docetaxel.
Her2 over-expression can be demonstrated by immunocytochemistry on paraffin processed tissue in most cases. However equivocal results can occur in a proportion of cases when demonstration of the gene amplification itself by FISH will clarify the result. Tissue which has been decalcified is not suitable for FISH
At Lab 21 we offer
2. HER2(ERBB2)/CEP17 FISH including interpretation (by prior arrangement) using the Abbott Molecular PathVysion™ HER2/CEP17 DNA Probe Kit
To request Her2 testing, the first point of contact is the dedicated Lab 21 Customer Services Team who handle:
- Test Requests and Customer Support
- Liaison with Sample Retention Sites for sample retrieval if required
- Reporting of the results
Tissue sections for FISH should be from specimens fixed in 10% neutral buffered formalin. These slides should be air dried then heated in an oven at 56-60 degrees for at least 60 mins.
1. The block to be tested should contain plenty of tumour material (>20%).
2. Safeguards should be undertaken to prevent sample-to-sample DNA contamination.
2a) Cleaning of the microtome and any equipment used in the sectioning area should be completed between the sampling of each block.
2b) Disposable blades provide the best means to eliminate block-to-block contamination.
2c) Change gloves between the cleaning of the microtome and the sectioning of each new block.
3. Send 2 unstained slides cut at 3μm on SuperFrost Plus, Leica Bond Plus or TOMO Slides & 1 H&E