The HER2 amplification probe consists of a 347kb probe labelled in red, spanning the HER2 (ERBB2) gene and neighbouring regions, and a green probe for the chromosome 17 centromere.
The HER2 (ERBB2) Human Epidermal growth factor Receptor 2 gene, located at chromosome band 17q12, is a member of the Epidermal Growth Factor (EGF) receptor family1.
It is activated and amplified in 20-30% of breast cancers2 and has been correlated with a poor prognosis for the patient3. Treatment of patients carrying the amplification using the monoclonal antibody Herceptin® (Trastuzumab) has been shown to be effective, increasing survival time by specifically targeting cells overexpressing HER24 and removing them from the system.
Similar results have been obtained for a variety of other malignant neoplasms overexpressing HER2 including ovarian5, stomach6, salivary gland7 and small cell lung8 cancers.