Avastin in metastatic breast cancer

Metastatic breast cancer MBC is a major cause of death among women worldwide. Progress has been made in treating MBC with the advent of anti-estrogen therapies, potent cytotoxic agents, and monoclonal antibodies. The FDA then reversed this decision in December by recommending removal of the MBC indication from bevacizumab, citing primarily safety concerns, and that these risks did not outweigh the ability of bevacizumab to significantly prolong progression-free survival. This decision was unexpected in the oncology community and remains controversial.

Disclosures: Ricardo H. Significant advances in the treatment of patients with breast cancer have been made in the past 10 years. The current systemic treatment of breast cancer is characterized by the discovery of multiple cancer targets leading to treatments that are more sophisticated and specific than conventional cytotoxic chemotherapy. Two classes of compounds that have helped improve clinical outcomes are small molecules and monoclonal antibodies targeting specific tyrosine kinase receptors. Many novel targets have been discovered, and parallel multiple approaches to anticancer therapy have recently emerged from the literature.

Tumor angiogenesis, which is necessary for breast cancer growth, invasion and metastases, is regulated by pro-angiogenic factors such as vascular endothelial growth factor VEGF. Bevacizumab is a recombinant humanized monoclonal antibody that targets VEGF. The addition of bevacizumab to chemotherapy has improved progression-free survival in the first- and second-line treatment of patients with advanced-stage breast cancer. In this article we review the clinical trials testing the utility of bevacizumab for the treatment of metastatic disease. The development of novel biologic agents that specifically target growth factor—receptor signaling pathways has led to significant advances in breast cancer treatment.

The case of Avastin and metastatic breast cancer reminds us of that simple, unfortunate fact once again. One of the most frustrating aspects of taking care of cancer patients is that in general, with only a few specific exceptions, we do not have good curative therapies for patients with stage IV cancer, particularly solid tumors. Over the years, we have thrown everything but the kitchen sink at patients with stage IV disease, largely with dissapointing results.