What is GENE ? Genes are segmentsof DNA located onchromosomes. Genes contain thecodes for theproduction of specificproteins.
HER2 Gene ? HER2 stands for HumanEpidermal growth factorReceptor 2. It is present onchromosome no 17. HER2 is a protein on thesurface of all normal cellsin your body. HER2 helps regulate theway cells grow and divideinto other cells.
NORMAL HER2vsCANCEROUS HER2YES ! Normal Cells have HER2 Gene !The difference is: Receptor over expression Dysregulation of receptor activation.
Diagnostic TestsThere are two tests for the detection of HER2 gene: IHC TEST( immunohistochemistry) FISH Testing( fluorescence in situ hybridization)Tests are usually performed on biopsy samplesobtained by either fine-needle aspiration, coreneedle biopsy, vacuum-assisted breast biopsy, orsurgical excision.
IMMUNOHISTOCHEMISTRY It’s a prognostic test. IHC is a protein-based test that is used toprovide an assessment of the amount of HER2protein receptors on the surface of the cancercells. IHC is the most commonly used test to see if atumor has too much of the HER2 receptorprotein on the surface of the cancer cells. Scoring for an IHC from 0 to 3+.
FISH TESTING FISH is a gene-based test used to determine thenumber of HER2 genes in the cells of the tumor.In HER2-positive breast cancer if there are toomany copies of the HER2 gene, the gene is“amplified." This test can be used to visualize specific genesor portions of genes. FISH is considered more accurate than IHC.
Treatment There are some treatments available specifically forHER2-positive breast cancer. The most commonly used medication is Herceptin(chemical name: trastuzumab), which works by attachingitself to the HER2 receptors on breast cancer cells andblocking them from receiving growth signals. By blocking these signals, Herceptin may help to slowor even stop the growth of the breast cancer. In addition to blocking HER2 receptors, Herceptin canalso help fight breast cancer by alerting the immunesystem to destroy cancer cells onto which it is attached.
Conclusion HER2-positive breast cancer is a breast cancer that testspositive for human epidermal growth factor receptor 2(HER2), which promotes the growth of cancer cells. In about 1 of every 5 breast cancers, the cancer cellsmake an excess of HER2 due to a gene mutation. This isa gene mutation that occurs only in the cancer cells and isnot a type of mutation that you can inherit from a parent. HER2-positive breast cancers tend to be more aggressivethan other types of breast cancer. Theyre also less responsive to hormone treatment.However, treatments that specifically target HER2 arevery effective.