Monitoring serum HER2 levels during neoadjuvant trastuzumab treatment within the GeparQuattro trial

摘要

In the context of neoadjuvant therapy (NT) for breast cancer patients, different targeted therapy approaches are currently evaluated in clinical trials. Serum markers could help to monitor and optimize such treatment strategies. We investigated human epidermal growth factor receptor 2 serum (sHER2) levels in 175 breast cancer patients participating in the GeparQuattro trial. This study incorporated NT approaches and additional trastuzumab treatment for all patients with HER2-positive tumors. Human epidermal growth factor receptor 2 serum levels were measured by enzyme-linked immunosorbent assay (ELISA) before initiation of NT and after NT (pre-surgery) in a HER2-positive (n = 90) and a HER2-negative patient cohort (n = 85). Median pre-chemotherapy sHER2 levels were higher in patients with positive HER2 status of the primary tumor than in patients with negative HER2 status (14.9 ng/ml vs. 7.7 ng/ml, P 0.05). Monitoring sHER2 levels in the presence of anti-HER2 treatment might be an adjunct to the clinical evaluation during NT.