“Inducing Angiogenesis” A Hallmark too Far

The term angiogenesis was coined in 1787 [1] and the role of vessels in cancer has being studied since. In 1971 Folkman [2] introduced the hypothesis, until now widely accepted, that tumour growth is angiogenesis dependent [3,4]. However, the discovery that tumours can also grow without angiogenesis, by co-opting pre existing vessels in humans [5-8] and in mice [9], has demonstrated that this is not always the case. This observation provides a new aspect of the interaction between vessels and tumours, sheds new light on the biology of the latter and has implications for resistance to antiangiogenic drugs and development of new vascular targeting strategies. Eventually the relationship between cancer and blood vessels is emerging as much more complex that was recently thought to be the case.