[Utility of serum human epidermal growth factor receptor-2 extracellular domain(HER2 ECD)assessment in patients with advanced or recurrent breast cancer and those who received neoadjuvant therapy].

Levels of serum human epidermal growth factor receptor-2 extracellular domain(HER2ECD )were measured in breast cancer patients. Fifty-six patients had advanced or recurrent disease, and 21 others were preoperation patients who received neoadjuvant therapy. In the tissue HER2-positive group of advanced or recurrent patients, levels of serum HER2ECD at first recurrence were high(≥15.