The role of adjuvant monoclonal antibody therapy for breast cancer: rationale and new studies.

HER2 is a member of the epidermal growth factor receptor (EGFR) family of tyrosine kinases and is involved in the growth, invasion, metastasis, and prognosis of breast cancer. The rationale for prospective trials evaluating the role of anti-HER2 monoclonal antibody therapy for patients with high-risk HER2-positive resected breast cancer is based on several factors. These include 1) the relative and absolute poor prognosis of patients with node-positive, HER2-positive breast cancer; 2) the emerging data of potential importance concerning anthracyclines as a component of adjuvant therapy for patients with HER2-positive breast cancer; 3) the role of taxanes in the management of patients with HER2-positive metastatic breast cancer; and 4) the feasibility and efficacy of molecularly targeted anti-HER2 monoclonal antibody treatment alone or in combination with chemotherapy for patients with advanced breast cancer.