SPoT-Light HER2 CISH

SPoT-Light HER2 CISH, which stands for Subtraction Probe Technology Chromogenic In Situ Hybridization, is a test used to determine whether breast cancer cells are HER2-positive. HER2-positive cells have too many HER2 receptor proteins at the cell surface. These receptors receive signals from outside the cell telling it to grow and divide. The medication called Herceptin (chemical name: trastuzumab) can block these signals from getting through.

The SPoT-Light HER2 CISH test, which was approved by the U.S. Food and Drug Administration in 2008, looks for HER2 genes in a breast cancer tissue sample. The SpoT-Light test uses a stain that makes HER2 genes change color. After the stain is applied to the breast cancer tissue, the sample is examined with a microscope. This shows how many copies of the HER2 gene are in tumor cells. When there are extra copies of the gene, there are extra receptor proteins at the cell surface.

The SPoT-Light test can be used on fresh tissue samples or tissue samples that have been stored in wax or other chemicals, but it doesn't work on frozen tissue samples.

With the SPoT-Light test, you get a score of either “HER2-positive” or “HER2-negative.” If the cancer is SPoT-Light positive, it will probably respond well to Herceptin.