Abstract
In 2005-2006, the Experimental Medicine Chair lecture focused on an important and highly topical subject : the development of new vessels in cancer and a novel therapeutic approach, the inhibition of neoangiogenesis in cancerous and metastatic processes. Cancers can only develop thanks to vessels supplying the oxygen and nutrients that cancer cells, which are major consumers of energy substrates, need for their growth. The proliferation of a tumor is inconceivable without the development of an appropriate vascularization, whether this involves the detour of pre-existing vessels to its benefit, or the de novo formation of tumor vessels. This led to the hypothesis that, by destroying the vessels irrigating the tumor, we could stop the growth of cancer cells or, at the very least, stabilize the tumor. This hypothesis, put forward by J. Folkman1 as early as 1971, was preceded by a series of observations suggesting a link between tumour growth and the development of vascularization. The discovery of VEGF, a crucial factor in vessel development in normal and pathological conditions such as cancer, played a decisive role in validating the concept of anti-angiogenic treatment in tumor pathology. Initial results obtained with an antibody blocking VEGF action in colon cancer with metastases have proved encouraging, and raise new questions : Are tumor blood vessels identical to normal vessels or, on the contrary, do they have their own specific markings ? how do they develop ? and how can their formation be stopped ? Is there not a risk of compromising circulation in normal tissues by trying to inhibit tumor vascularization ? What results have been obtained in humans with different types of cancer ? In a word, are the hopes placed in the logic of this new therapeutic strategy justified ? The lecture given by the Chair of Experimental Medicine has attempted to answer some of these questions.
Note
1. Folkman J., New Engl. J. Med. 1971.