Longitudinal changes in serum HER-2/neu oncoprotein levels in trastuzumab-treated metastatic breast cancer patients.

Background: To evaluate longitudinal variations of serum HER-2/neu extracellular domain (sHER-2) in metastatic breast cancer patients receiving combined trastuzumab treatment.

Patients And Methods: Thirty-three patients were monitored by serial sHER-2 ELISA (Oncogene Science). Results were compared to time to progression (TTP) and survival from treatment initiation.

Serum HER-2 extracellular domain (ECD) before the first metastasis in 128 breast cancer patients.

We studied the serum HER-2 extracellular domain (sHER-2) before the first metastases in 128/701 breast cancer patients diagnosed and followed-up in our institution who developed metastases as the first relapse. sHER-2 was measured by an enzyme-linked immnunosorbent assay and CA 15.3 by an immunoradiometric assay.