Anti-angiogenic strategies in gastrointestinal malignancies.

Advances in our understanding of the mechanisms underlying tumor progression suggest that angiogenesis plays a key role in gastrointestinal malignancies. Vascular endothelial growth factor (VEGF) has emerged as an important therapeutic target, and a variety of strategies to inhibit VEGF are under investigation. The approval of bevacizumab for use in patients with previously untreated metastatic colorectal cancer was based on clinical data suggesting that VEGF is a valid therapeutic target in this disease. As the data mature from ongoing trials, the role of angiogenesis inhibitors in the treatment of colon cancer and other gastrointestinal malignancies will be more clearly defined. Additional information is needed to identify the diseases and stages most likely to benefit from anti-angiogenic agents and the optimal sequences and therapeutic combinations that should be studied.