Do smokers with asthma have a greater chance of getting lung cancer than smokers who don’t have asthma?
The answer may be yes if they have emphysema.
But then again, maybe not.
I’m not sure if either study considered that people with pre-existing lung conditions are more likely to get chest x-rays and are thus more likely to have their cancers detected. People without pre-existing respiratory conditions may therefore be more likely to have undetected cancers. They may die from something else before the cancer is diagnosed (smokers drop for all types of reasons).
The question seems much harder to answer than I would have thought.
Cheers, Karl. That was very helpful.