The role of bevacizumab in colorectal cancer: understanding its benefits and limitations.

INTRODUCTION: Angiogenesis is a key factor in the development of aberrant blood vessels required for malignant growth, invasion and progression. Inhibiting VEGF is by far the most clinically advanced anti-angiogenic target. Bevacizumab (BV), the only humanized mAb directed against VEGF, is approved for use in multiple tumor types after successful clinical trial results demonstrated benefits in progression-free survival and/or overall survival when combined with common cytotoxic chemotherapies. AREAS COVERED: The review focuses on the use of BV in colorectal cancer, discusses the clinical trial data supporting its increasing use and explores its limitations. Readers will gain a succinct description of the trial data demonstrating a modest survival benefit in metastatic colorectal cancer (mCRC) and the lack of benefit of BV when utilized in the adjuvant setting. A review of common BV toxicities and a discussion about possible BV resistance mechanisms are also provided. EXPERT OPINION: Although BV has demonstrated efficacy in mCRC, there is an urgent need to improve the understanding of its mechanism of action and the development of BV resistance. Furthermore, there is a need for delineating predictive markers of BV efficacy and toxicity.