Cancer may not be the key to immortality after all

My KISS way of explaining cancer [used to be] this:

Cancer cells are basically cells that have discovered the key to immortality. They don't "know" when to die, and just keep on living and doing what they do. The crap thing is that generally its only a small part of your body that works this out at once. And as I mentioned before you don't need spleen cells where your skin cells should be (or vice versa). So, ergo, the real key to immortality, the fountian of youth if you will, would be to have every cell in your body become cancerous at once - barring any Akira-like transmogrification - the competing tumors will combat each other and hopefully establish an equilibrium, and you can continue living harmoniously without any need for the beautiful side effects of chemo. While I'm spewing crap I could also mention this might be a non-endo-symbiotic pathway in the developmen of multi-cellular organisms.

Like a lot of my KISS explanations, it can tend not to end up making a lot of sense towards the end, lack a clear point, and research keeps causing me to rethink.

Scientist have shown that there is a link between longetivity and tumor-supression. Bastards.