A promising new treatment for cancer starves tumors of their blood supply.
Robert Weinberg, PhD
Daniel K. Ludwig Professor for Cancer Research
Massachusetts Institute of Technology
If we consider all of the various kinds of cells that are recruited into a tumor mass, perhaps the most important kind of cells that are recruited by the cancer cells are so-called endothelial cells, and these endothelial cells are specialized to make blood vessels, to make capillaries, why are the cancers to interested to recruit endothelial cells into the tumor mass? Simply because a cancer, a tumor tissue, requires a blood supply just like normal tissue. And therefore, without such a blood supply a tumor cannot grow to a diameter of more than lets say 1 or 2/10ths of a millimeter. Therefore the tumor needs a direct blood supply and how it does that is it seduces blood vessels to grow into the tumor mass, thereby supplying the cells in the tumor mass with nutrition and oxygen and thereby enabling the tumor mass to rid itself of carbon dioxide and all kinds of metabolic wastes that it needs to get rid of so that it doesn't poison itself.
A highly attractive strategy for treating many kinds of cancers is to interrupt the recruitment of many endothelial cells by cancer cells. This recruitment leads to a process of blood cell formation which we call angiogenesis. And if one can block angiogenesis, one can prevent these endothelial cells from being recruited into the tumor mass and thereby block the cancer cells from getting access to the circulation and the much needed nutrients and oxygen that are carried by blood.
Until now attempts at interrupting angiogenesis have succeeded in a small number of tumors, but the anti-angiogenesis therapies have not yet been put into clinical practice because the success to date have been few and far between. However, if I were a betting man, and I am, I would bet there will be some striking successes in improving anti-angiogenesis therapy to the stage that it will be useful in treating many kinds of human tumors.