Review: The potential role of bevacizumab in early stages and locally advanced non-small cell lung cancer

Improving outcomes for early-stage non-small cell lung cancer (NSCLC) is a major research area considering that a significant percentage of such patients develop recurrent disease within 5 years of complete lung resection. Adjuvant chemotherapy prolongs survival, with an absolute improvement in 5-year overall survival of about 5% with drawbacks such as treatment toxicity. Approximately, one third of patients with newly diagnosed NSCLC have locally advanced disease not amenable for surgical resection - in this setting of patients concurrent chemoradiation is the standard of therapy. However, the treatment of locally advanced NSCLC is still controversial and clinical outcomes are disappointing, and so new approaches are required to improve the clinical benefit in this setting of patients. Vascular endothelial growth factor (VEGF) is a key angiogenic factor implicated in tumor blood vessels formation and permeability, and tumor VEGF overexpression in patients with early stage lung cancer has been associated with worse relapse free and overall survival. Several agents have been developed that inhibit VEGF or its receptor signalling system. Bevacizumab is the first recombinant humanized monoclonal antibody binding VEGF to demonstrate clinical benefit or rather a survival prolongation in combination with chemotherapy in the treatment of non-squamous advanced NSCLC patients. These positive results led to a large number of clinical trials to evaluate bevacizumab in combination with other targeted agents in advanced disease, and to define the role of this agent in early stage NSCLC such as the impact of bevacizumab integration in chemoradiotherapy strategy for locally advanced disease.