Clinical Application of Antiangiogenic Therapy: Microvessel Density, What It Does and Doesn't Tell Us

A substantial number of clinical trials using antiangiogenic therapies are ongoing worldwide. How to achieve the maximum benefit from these therapies and how to monitor patient response are of paramount concern to investigators. There are currently no markers of the net angiogenic activity of a tumor available to aid investigators in the design of antiangiogenic treatment schemes. It stands to reason that quantification of various aspects of tumor vasculature might provide an indication of angiogenic activity. One often-quantified aspect of tumor vasculature is microvessel density. Studies over the last decade have demonstrated the value of using tumor microvessel density as a prognostic indicator for a wide…