Feasibility trial of letrozole in combination with bevacizumab in patients with metastatic breast cancer.

Purpose: Preclinical models suggest that the use of anti-vascular endothelial growth factor (anti-VEGF) therapy with antiestrogens may prevent or delay the development of endocrine therapy resistance. We therefore performed a feasibility study to evaluate the safety of letrozole plus bevacizumab in patients with hormone receptor-positive metastatic breast cancer (MBC).

Methods: Patients with locally advanced breast cancer or MBC were treated with the aromatase inhibitor (AI) letrozole (2.