Introduction to Clinical Oncology
Sustained Angiogensis: the 5th hallmark of cancer

Sustained Angiogensis: the 5th hallmark of cancer

In normal tissues, the development of new blood vessels is highly regulated by both positive and negative signals.

Tumours often outgrow their blood supply and must actively recruit vasculature in order to continue to grow.

Without vascularization tumour nodules cannot grow larger than 1-2 mm.

Tumor cells promote angiogenesis by upregulating the pathways that promote blood vessel formation (e.g. increased expression of growth factors such as vascular endothelial and fibroblast growth factors) and by reducing the activity of inhibitory pathways.