Capillary density has no value as an early biomarker of bevacizumab efficacy in metastatic colorectal cancers: a prospective clinical trial.

Background: Bevacizumab is a recombinant humanized monoclonal immunoglobulin G1 antibody targeting VEGF-A. It is currently used with chemotherapy as the first- or second-line therapy in metastatic colorectal cancer. Previous studies have showed that anti-angiogenic agents decrease capillary density.