The combination of VEGF inhibitors and anti-oestrogen therapies in breast cancer

Despite effective treatments for oestrogen receptor-positive breast cancers, drug resistance is common and remains a significant clinical challenge. Targeting tumour vasculature by blockade of the vascular endothelial growth factor (VEGF) has proved successful in a variety of cancers. Phase III clinical trials of bevacizumab in combination with chemotherapy showed some efficacy in breast cancer. Concomitant targeting of the VEGF and oestrogen signalling pathways has the potential to provide enhanced therapeutic benefit in oestrogen receptor-positive breast cancer, and this strategy is under evaluation in clinical trials. This article summarises the rationale for this approach and clinical studies so far.