Biomarkers measure disease progression and the efficacy of treatment. Siemens Medical Solutions Diagnostics is bringing medical oncologists a serum HER-2/neu biomarker test for monitoring metastatic breast cancer.

Professor Jean-Pierre Lotz, MD, Chief Medical Oncologist at Université Pierre et Marie Curie’s Hôpital Tenon in Paris, France, said that he began studying the serum test five years ago, at the directive of the French Ministry of Health.

The serum test measures circulating HER-2/neu extracellular domain (ECD); longitudinal changes in serum levels reflect the effectiveness of treatment. Lotz says that baseline serum tests are necessary to see longitudinal changes, which could guide therapy. “My first experiences with measuring serum HER-2/neu for metastatic breast cancer showed that after patients were given chemotherapy, if the treatment was working, serum levels would rapidly decrease in the first three to four weeks after treatment,” says Lotz. “We confirmed our serum readings with a CT scan.” Christine Druther, MSPH, breast cancer survivor and founder of the HER-2 Support Group, calls it a “wonderful” test that monitors progression when other serum tests, such as CA15-3 and CA-125, fail. “People who are not getting it are being underserved,” says Druther.