What really DOES cause cancer? You know, cigarettes don't actually give you cancer, for instance. It just raises the risk. That's why some people never smoke, but still get lung cancer. While some people smoke their whole lives without getting lung cancer.
I think this thread is lacking a little in terms of a well-constructed opening post. Cancer is a fine discussion topic, or even the overabundence of things that supposedly 'cause' cancer, but you'd have to more clearly define what it is you want to discuss.