The Serum HER-2/neu Test is a test that can track a woman’s HER-2/neu level once she is diagnosed with MBC regardless of whether the treatment is hormone therapy, chemotherapy or trastuzumab-based therapy because it is a serum biomarker for HER-2/neu positive tumors. Recent clinical studies have also shown that up to 40% of breast cancer patients who had HER-2/neu negative tumors at first diagnosis later became HER-2/neu positive.(iv) The Serum HER-2/neu Test allows physicians to identify patients whose original tissue biopsies were HER-2/neu negative, not tested, not available for testing, or were stored for a long period of time, but who subsequently become positive after their cancers have spread. It is a more recent test and it ahs not been validated vis-a-vvis tumor HER testing in rpedicting the effect of Herceptin.
A recent review concludes: “On the basis of our review of the literature, we conclude that there is currently insufficient evidence to support the use of serum HER-2 ECD in the routine management of individual patients with breast cancer. This conclusion is in agreement with the 2007 American Society of Clinical Oncology guidelines on the use of biomarkers in breast cancer. ” This test cannot serve as the basis for approving Herceptin in lieu or against HER/2neu results on teh tunor specimen.
|Leary, Alexandra F., Hanna, Wedad M., van de Vijver, Marc J., Penault-Llorca, Frederique, Ruschoff, Josef, Osamura, Robert Y., Bilous, Michael, Dowsett, Mitch
Value and Limitations of Measuring HER-2 Extracellular Domain in the Serum of Breast Cancer Patients
J Clin Oncol 2009 27: 1694-1705