Why couldn't some forms of cancer treatment be like dialysis. If your blood was run through an external treatment then put back into your body, that might just get rid of cancer cells. My reasoning is this; I have read that most cancer cells are like viruses. When we have viruses, our bodies sometimes develop high temperatures. I think that this is natures way of killing infection. Why not run the blood through a device outside of our bodies that either subjects the blood to heat or cold, filters out the dead cells, cools or warms the blood to normal temperature, then returns the blood back to the body. In some cases the cancer cells might be killed by subjecting the blood to UV light. Or why not even treat the blood externally with known cancer treatments. This may be less uncomfortable for the patient than current methods.