I wonder if the immune system plays a role. In one environment there is some stressor (e.g. smoking) which raises for example lung cancer risk, but also turns u

I wonder if the immune system plays a role. In one environment there is some stressor (e.g. smoking) which raises for example lung cancer risk, but also turns up some built-in anti-cancer systems in the body - the action of which which would prevent cancers in other areas. Compare to a person in a better environment where the immune system isn't as much in "cancer-prevention mode".