FDA approves HER2 test for breast cancer

A genetic test to determine whether a breast cancer patient is likely to respond to treatment with the drug Herceptin (trastuzumab) has been approved by the U.S. Food and Drug Administration.

The SPOT-Light HER2 CISH kit helps calculate how many copies of the HER2 gene, which regulates the growth of cancer cells, are in tumour tissue. A healthy breast cell should have two copies of the HER2 gene, but patients with breast cancer may have many more. Since the gene signals cells when to grow, divide and make repairs, too many copies may cause cells to grow and divide too rapidly.

Herceptin targets HER2 protein, helping stop the growth of such cancer cells in breast cancer patients overproducing that particular protein. HER2 is overexpressed in about 30% of breast cancer cases.

This test can potential provide health care professionals with additional insight on treatment decisions for patients with breast cancer when used with other clinical information and laboratory tests.

The SPOT-Light test counts HER2 genes through a chemically stained sample of removed tumor observed under a standard microscope. Previous tests required more expensive and complex fluorescent microscopes. The SPOT-Light also allows labs to store the tissue for later reference, a feature not possible with previously available tests.