The approach to antiangiogenic therapy in cancer patients

Abstract

New vessel formation facilitates local tumor progression and distant metastases formation. Angiogenesis is a very complex process, which demands well-coordinated activity of various factors during consecutive steps. The balance between pro- and antiangiogenic factors shifted towards the former ones is a prerequisite for the initiation of angiogenesis. VEGF is the most important factor contributing to the new vessel formation. Its biological activity depends on the presence and activity of different receptors, eg. VEGFR-2, VEGFR-1, neuropilin 1, Tie2 receptor system, ephrin system, etc.
In experimental models blocking VEGF activity results in diminished interstitial pressure and improved cytotoxic drugs tissue penetration. In clinical settings, interfering with VEGF activity allowed for improved treatment outcomes in cancer patients. However, despite promising results, many questions remain opened, eg. the optimal selection of cancer patients for such a treatment, the way of therapy monitoring as well as the length of antiangiogenic treatment.