The cancer patients who die of their disease are the ones who experience metastatic spread of their tumors. Even with the most aggressive conventional treatment, only 5 to 10 percent of these patients will survive long term.For the other 90 to 95 percent, the grueling, enormously expensive treatment will add no more than a few months to their lives. In fact, there’s evidence that those undergoing radical cancer treatment actually die sooner.

Many years ago, when I was studying cancer in medical school, it occurred to me that cancer acted very much like a parasite, living off of its host. I noticed that cancer cells used many of the host’s biochemical systems to grow and spread.

The cancers also utilized a number of mechanisms to keep the host’s body from rejecting them. At the time such a theory was unheard of, but today many other scientists share this idea.

This does not mean that cancer is actually a parasite that crawls into your body like a worm. It’s just to say that cancer acts somewhat like that worm once it is in the body.

As you learn the intricacies of cancer, you begin to appreciate that cancer cells anticipate all of the methods the body can use to kill them, and devise methods to either neutralize those mechanisms or evade them.

For example, each cell in the body has a “suicide” gene that lies dormant in its genetic structure. Should the cell become damaged by something like free radicals, this dormant suicide gene (called the p53 gene) wakes up and activates a series of chemical reactions that ultimately kill the cell.

The purpose of this system is to keep the cell from becoming a cancer. More than half of all cancer cells have been found to have damaged (that is, mutated) p53 suicide genes.

The rest of the cells probably have some kind of impaired function. It is the cancer stem cell that does this dirty work.

Another way cancer stem cells protect the cancer is to make them invisible to the immune system. Normally, the immune system sends special cells around the body to look for cells that are dangerously close to becoming or have become cancer stem cells. Once found they find one of these cells, their job is to kill it.

But cancer stem cells have a special mechanism that makes them invisible to the immune system. This “cloaking” is actually a process the cancer stem cell hijacks from the body’s normal protective immune responses.

With the body’s recognition system essentially turned off, the immune cells simply never see the cancer.