How is HER2 amplification tested?
Currently, two methods of determining HER2 status are used routinely in clinical practice: immunohistochemistry (IHC), which assesses expression of the HER2 protein on the cell surface, and fluorescent in situ hybridisation (FISH), which detects amplification of the HER2 gene (Pauletti et al, 2000; Bartlett et al, 2001 …
What does amplification of HER2 mean?
HER2 proteins are receptors on breast cells. Normally, HER2 receptors help control how a healthy breast cell grows, divides, and repairs itself. But in about 10% to 20% of breast cancers, the HER2 gene doesn’t work correctly and makes too many copies of itself (known as HER2 gene amplification).
What is the role of HER2?
HER2 acts as a networking receptor that mediates signaling to cancer cells, causing them to proliferate. HER receptors exist as monomers but dimerize on ligand binding. HER ligands are bivalent growth factor molecules whose low-affinity site binds to HER2.
What causes HER2 gene amplification?
This is caused by a mutation in the HER2 (human epidermal growth factor receptor 2) gene. When the HER2 gene mutates, it causes cells in the breast to grow and divide at an uncontrolled rate, leading to tumor growth.
How do you read HER2 FISH results?
- Positive HER2 amplification: FISH ratio is greater than 2.2 or HER2 gene copy is greater than 6.0.
- Equivocal HER2 amplification: FISH ratio of 1.8-2.2 or HER2 gene copy of 4.0-6.0.
- Negative HER2 amplification: FISH ratio is less than 1.8 or HER2 gene copy of less than 4.0.
What causes amplification of HER2?
In about 25 percent of breast cancers, the cancer cells have an excess of the HER2 protein. This is caused by a mutation in the HER2 (human epidermal growth factor receptor 2) gene. When the HER2 gene mutates, it causes cells in the breast to grow and divide at an uncontrolled rate, leading to tumor growth.
Does everyone have HER2 gene?
Everyone has both BRCA1 and BRCA2 genes. Like the HER2 gene, they’re designed to repair cell damage and help restore normal, healthy breast cells. In some people, however, these genes stop performing properly.
What does positive FISH test mean?
FISH testing usually returns one of two results: positive or negative. Positive means your breast cancer cells make too much HER2 and your doctor should treat you with drugs that target that protein. Negative means the protein isn’t involved in the growth of your tumor.
Why is HER2 IHC score 2 + important?
Thus, IHC score 2+ is considered to be an indication for a confirmatory gene based test (FISH or CISH). Because of its central importance in breast cancer therapy selection, standardization of HER-2 IHC assays and slide interpretation are of outmost clinical and economical importance.
Which is the best Test to check for HER2?
Current guidelines recommend using either IHC or ISH to assess tumour HER2 status for all patients with breast cancer. Both tests are used, in case an equivocal result is obtained with the first test [ 3, 10 ].
What is the pass rate of nordiqc PMS2?
PMS2: 302 laboratories participated and obtained a pass rate of 70% (43% optimal). This was the third NordiQC assessment of PMS2 and a decrease in the pass rate was seen compared to the previous runs.
What’s the IHC score for Herceptin 2 +?
True responses to Herceptin occur in this category of 2+ positive tumours. Thus, IHC score 2+ is considered to be an indication for a confirmatory gene based test (FISH or CISH).