I don't think curing cancer makes much sense in the Kickstarter sense: 1. It is enormously expensive - curing a form of cancer costs well into the millions. So it wouldn't get funded. 2. There are loads of funding sources out there already. 3. "Curing" is actually very difficult to define. Most cancer treatments reduce and you'd need a bunch of expensive studies just to determine if the metric was met if it was anything short of "cured."

That said, it might work on a limited basis if you applied an X-Prize to certain forms of cancer. It could mobilize people to really focus on certain types of cancer and specific goals.