New Genetic Test Aids Detection of HER2+ Breast Cancer

On Tuesday the FDA approved a genetic test known as Inform Dual ISH. The test will determine if women with breast cancer are HER2+, a condition that presents in approximately 20% of women diagnosed with breast cancer.

The Inform Dual ISH test facilitates measurement of the HER2 genes, which present on chromosome 17 in human cells. The test colors the HER2 genes black and chromosome 17 red, allowing the genes to be counted. Patients with a larger than normal amount of the HER2 gene are considered eligible for treatment with trastuzumab (Herceptin), an adjuvant treatment for patients with HER2+ breast cancer.

In a study examining 510 breast cancer patients, the test proved to be 96% accurate at detecting more than the normal amount of the HER2 gene and 92.3% accurate at detecting less than the normal quanity of HER2.

The Inform Dual ISH test is different from other HER2 tests in that it allows the use of a standard microscope to view specimen results; past tests required a fluorescence microscope. This unique attribute of the test allows lab staff the ability to see the number of HER2 genes more readily and for longer periods of time.

"When used with other clinical information and laboratory tests, this test can provide healthcare professionals with additional insight on treatment decisions for patients with breast cancer," said Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostic Device Evaluation and Safety in the FDA’s Center for Devices and Radiological Health.

The test will aid in the treatment of 41,418 of the estimated 207,090 new cases of breast cancer diagnosed each year in the United States. Breast cancer claims the life of 39,840 women each year in the US making it the second leading cause of cancer-related death among women, according to the National Cancer Institute.

Inform Dual ISH is manufactured by Ventana Medical Systems in Tucson, Arizona, and Genentech manufactures Herceptin. Both companies are members of the Roche Group.