The risk of developing metastatic disease in colorectal cancer is related to CD105-positive vessel count

Background and Objectives: Angiogenesis is a complex multistep process that involves extracellular matrix remodeling, migration and proliferation of endothelial cells, and morphogenesis of microvessels. CD105 (endoglin), a co-receptor of the TGF-beta superfamily, was proposed as a marker of neovascularization in solid malignancies. The aim of this study was to evaluate retrospectively the effect of CD105-assessed angiogenesis on the risk of developing metastatic disease in colorectal cancer (CRC). Methods: One hundred and twenty-five paraffin-embedded samples were analyzed by immunohistochemical methods using a CD105 monoclonal antibody. The median follow-up was 70.8 months. Survivals were calculated from actuarial estimates, and logistic regression predicted the risk of developing metastatic disease. Results: The CD105-vessel count was strongly correlated with the occurrence of metastatic disease. The median CD105-positive vessels in patients with and without metastatic disease were 24.7 and 13.2 vessels/mm(2), respectively (P < 0.001). For each one microvessel increase in the vessels count per 400x field, there was a 1.42-fold increase in the risk of metastatic disease (P < 0.001). Conclusions: The assessment of tumor angiogenesis with anti-CD105 was not sufficient for its use as a surrogate end point for survival because of the amount of survival Variability explained was only 8% in absence of metastatic disease. In contrast, multivariate logistic regression analysis revealed that CD105-vessels count can identify patients at high risk of metastatic disease.