You could consider this an artificially selected population, since to keep an airline transport pilot license it is required to maintain a current FAA medical. I'm sure lots of pilots smoke, drink and eat poorly, but they try to avoid getting grounded and career-ended by their physician.
There was a good study and results that just came out about this in the past couple of weeks and it backs up that airline crew have higher cancer rates:
In plainer, much less careful English: even with that exposure, they live longer than average.
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4511278/