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World J Gastroenterol. Aug 21, 2013; 19(31): 5051-5060
Published online Aug 21, 2013. doi: 10.3748/wjg.v19.i31.5051
Role of bevacizumab in colorectal cancer growth and its adverse effects: A review
Efstathios T Pavlidis, Theodoros E Pavlidis
Efstathios T Pavlidis, Theodoros E Pavlidis, Second Surgical Propedeutic Department, Medical School, Aristotle University of Thessaloniki, Hippocration Hospital, 54642 Thessaloniki, Greece
Author contributions: Pavlidis TE designed the research, contributed to the new reagents and analytic tools and analyzed the data; Pavlidis ET performed the research and wrote the paper.
Correspondence to: Theodoros E Pavlidis, MD, PhD, Professor, Second Surgical Propedeutic Department, Medical School, Aristotle University of Thessaloniki, Hippocration Hospital, Konstantinoupoleos 49, 54642 Thessaloniki, Greece.
Telephone: +30-2310-992861 Fax: +30-2310-992932
Received: May 29, 2013
Revised: July 7, 2013
Accepted: July 19, 2013
Published online: August 21, 2013

Angiogenesis affects both wound healing and malignant cell growth through nutrients and oxygen. Vascular endothelial growth factor (VEGF) is the most important element involved in this complex process. Inhibition of VEGF influences angiogenesis and may restrict tumor growth and metastatic ability. Modern anti-angiogenic therapy is based on this theory. Bevacizumab is a recombinant humanized monoclonal antibody (immunoglobulin G1) which binds with VEGF-A forming a large molecule. It can not be bound with VEGF tyrosine kinase receptors preventing VEGF-A incorporation; thus its activity is inhibited inducing blockage of VEGF-mediated angiogenesis. Bevacizumab, in combination with chemotherapy or other novel targeted therapeutic agents, is currently used more frequently in clinical practice, mainly for managing advanced colorectal cancer. It is also used for managing other malignancies, such as breast cancer, pancreatic cancer, prostate cancer, non small-cell lung cancer, metastatic renal carcinoma and ovarian tumors. Although it is generally considered a safe treatment, there are reports of some rare side effects which should be taken into account. Recent experiments in rats and mice show promising results with a wider therapeutic range.

Keywords: Angiogenesis, Vascular endothelial growth factor, Anti-angiogenic agents, Bevacizumab, Avastin, Cancer targeted therapy, Colorectal cancer

Core tip: Modern targeted therapy with anti-angiogenic agents is based on inhibition of angiogenesis, as the formation of new vessels is crucial for the growth and metastasis of malignant cells. Recent studies on the biological agent, bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor activity, have shown improved outcome in advanced colorectal cancer. The combination of irinotecan, capecitabine and bevacizumab is currently the most frequently used regime in the treatment of metastatic colorectal cancer with improved response rates. However, the rare side-effects of bevacizumab should always be considered.