I think we are seeing more and more that genetics play a bigger part in our overall health than one would previously believe. There are people who could smoke 2 packs of cigarettes a day and live to be 80, and there are those who will never smoke and be dead of cancer at 50. Assuming everything else is equal (diet, environment, etc) the only answer is genetics. As we unlock DNA further and further we will see a paradigm shift in medicine to preventative care rather than reactive care. In 10-15 years, doctors will be able to tell you everything about your medical future after a simple DNA test, and act accordingly.
Cancer is not something I would wish on anyone, and like Don Schumacher said, our current treatments for the disease are barbaric. But Larry survived and his future looks bright. When he gets back in a car I have little doubt he will be successful. (see: Beckman, Jack)