The general explanation that is given for this phenomenon is that, in order for tumor cells to grow quickly, they must stimulate the production of blood vessels. VEGF and other growth factors are involved in cancer angiogenesis. Tumor cell aggregates as small as 150–200 μm, start to become dependent on blood supply carried out by neovasculature for their nutritional and oxygen supply.
The general explanation given for this phenomenon is that, in order for tumor cells to grow rapidly, they must stimulate the production of blood vessels. Vascular endothelial growth factor (VEGF) and other growth factors are involved in cancer angiogenesis. Tumor cell aggregates as small as 150–200 μm, begin to rely on blood supply provided by newly formed blood vessels for their nutritional and oxygen needs.