Serum HER‐2/<i>neu</i> and relative resistance to trastuzumab‐based therapy in patients with metastatic breast cancer

In this pooled analysis of 307 patients with MBC, individuals who did not achieve a significant decline (>or=20%) in serum HER-2/neu levels had decreased benefit from trastuzumab-based therapy, and these patients should be considered for clinical trials evaluating additional HER-2/neu-targeted interventions.