HER2 FISH (ERBB2)
HER2/NEU FISH
- Tech Only CPT
- Tech Pro CPT
- PowerPath Code FISH-HER2 BR, FISH-HER2 GI, FISH-HER2 CO, FISH HER2 USC
- Schedule Monday - Friday
- Turn Around Time 4-7 Days
- Disease State Breast Cancer, Colon cancer, Gastric Cancer, Uterine Serous Carcinoma
- Methodology FISH
Specimen Requirements
Formalin-fixed, paraffin-embedded tissue blocks; fixed in 10% neutral-buffered formalin for at least 6 hours, and not more than 72 hours. Tissue should be prepared in sections at 4 microns thick. Sections should be mounted on the positive side of an organosilane-coated slide in order to minimize detachment of the tissue from the slide during FISH assay.
Diagnostic Utility
HER2 (c-erbB-2) oncoprotein is a 185 kDa transmembrane tyrosine kinase receptor which is overexpressed in 10-20% of breast cancers and 15-20% of gastric cancers, primarily through gene amplification. It is a prognostic and predictive marker, and HER2 status is tested in all cases of invasive breast carcinoma and in a subset of gastric, colon and uterine serous cancers to determine the use of trastuzumab (Herceptin) and other HER2-targeted therapies. The HER2 fluorescent in situ hybridization (FISH) assay evaluates for HER2 gene amplification using a dual probe system targeting the HER2 gene and the chromosome 17 centromere.
Storage and Transportation
Room temperature or refrigerated. Ship in cooled container during summer months.
Cause for Rejection
Specimen containers without two (2) patient identifiers. Tissue not verified for the presence of invasive carcinoma, carcinoma in situ, and specimens fixed in fixatives other than formalin are not acceptable. Surgical pathology report should be included. Decalcification compromises the specimen quality, recomend EDTA decal.
Retention
10 years FFPE
Comments
Only tissue that is clearly invasive carcinoma (established by histopathologic criteria) should be tested. Selection of tissue for the FISH assay should be performed by a pathologist.