First-line Treatment of Metastatic Breast Cancer: Focus on Bevacizumab

As vascular endothelial growth factor (VEGF) plays a central role in tumor growth, invasion and metastasis, inhibiting tumor angiogenesis by blocking the actions of VEGF is a rational therapeutic strategy. Drugs targeting the VEGF system are currently in development and at the most advanced stage of development is bevacizumab. The effect of bevacizumab on breast cancer has been examined in many clinical trials, and promising results have been reported. The clinical effect of bevacizumab monotherapy for breast cancer is not clear; however, the ECOG-E2100 study showed that first-line anti-angiogenic therapy using bevacizumab combined with paclitaxel clearly improved the response for earlier stage metastatic breast cancer (MBC). As a stronger anti-tumor effect is expected when prescribing bevacizumab for patients at an early stage of MBC, many first-line clinical trials using bevacizumab with other combination regimens are currently ongoing. Although the common side effects of bevacizumab are hypertension, proteinuria, wound-healing complications, and thromboembolism, it is a comparatively safe agent. It is expected that the many ongoing clinical trials will establish bevacizumab as a standard first-line therapy for MBC.