The US Food and Drug Administration (FDA) has approved Inform Dual ISH (Ventana Medical Systems), a genetic test that allows for measurement of the number of copies of the HER2 gene in tumor tissue. This method of identification of women with breast cancer who are HER2-positive pinpoints who is, and who is not, a candidate for Herceptin (trastuzumab).
With this test lab staff can stain the sample with chemicals that cause copies of HER2 genes and chromosome 17 to change color, thus allowing them to see the HER2 and chromosome 17 signals directly under a microscope, for longer periods of time.
Approval was based on a US study of tumor samples from 510 patients with breast cancer, which showed the test correctly confirmed 96% of HER2-positive tissues.
Read the FDA announcement: