I agree in a long term sense (we'll figure it out eventually, and fuck evolution), but I don't think we can assume evolution leaves us in a situation where cancer is easy to solve, and we just need to tie off some loose ends, or turn up a few knobs. And I don't think the understanding of cancer levels in, say, whales is developed to do more than guess something is going on. Some theories suggest better repair mechanisms, others that it's simply different selective effects at the cellular level in larger organisms.