- glossary ON | OFF
- |
-
text zoom - |
- e-mail page
- |
- print page
Focus on HER2 detection methods
Slide Deck
View the HER2 slide deck
Commonly used methods of HER2 status detection
This image shows determination of HER2 status in 4 samples of breast tumor tissue. Samples A and B were analyzed by immunohistochemistry (IHC), while samples C and D were analyzed by fluorescence in situ hybridization (FISH). IHC detects protein and shows an increased expression of HER2 receptors, while FISH detects gene amplification.
Sample A shows normal levels of HER2 protein expression, and sample C shows normal copy numbers of HER2 genes, while samples B and D show abnormal levels, respectively.6 Role of HER2 gene expression in breast carcinoma. Ménard S, Tagliabue E, Campiglio M, Pupa SM. Copyright © 2000 J Cell Phys; Reprinted with permission of Wiley-Liss, Inc., a subsidiary of John Wiley & Sons, Inc.
Sample A shows normal levels of HER2 protein expression, and sample C shows normal copy numbers of HER2 genes, while samples B and D show abnormal levels, respectively.6 Role of HER2 gene expression in breast carcinoma. Ménard S, Tagliabue E, Campiglio M, Pupa SM. Copyright © 2000 J Cell Phys; Reprinted with permission of Wiley-Liss, Inc., a subsidiary of John Wiley & Sons, Inc.
How is HER2 measured?
HER2 can be determined by any of several methods. The most commonly used methods are7:
- Fluorescence in situ hybridization (FISH), which detects gene amplification by measuring the number of copies of the HER2 gene in the nuclei of tumor cells3
- Immunohistochemistry (IHC), which measures the number of HER2 receptors on the cell surface and therefore detects receptor overexpression3
Other methods of HER2 testing have been used increasingly in clinical studies and may eventually be incorporated into routine practice. These include:
- Chromogenic in situ hybridization (CISH), which measures gene amplification using a light microscope rather than a fluorescent microscope, which is required for FISH8,9
- Reverse-transcriptase polymerase chain reaction (RT-PCR), which detects HER2 gene amplification8
Is HER2 testing accurate?
- Both IHC and FISH test results can be affected by testing conditions including the use of suboptimally fixed tissue, failure to use specified reagents, deviation from specific instructions, and failure to include appropriate controls10
- In order to increase the accuracy of HER2 testing results, testing should be performed by laboratories with demonstrated aptitude in the specific test requested10
- Studies have shown that large-volume laboratories provide reputable test results10
