Anecdotally, as an ex-smoker who quit after my mother died from lung cancer, I spoke to my doctor about screening. He did a lot of dismissing and hand waving about it. It upset me greatly at the time. This article explains it all well enough. Doctor/patient communication is very important.
How long did you smoke? My own anecdote: I was athletic when I was younger, but I was a regular smoker through most of my twenties. I quit a few years back. My doctor would check my breathing, etc, with everything I'd told him about my habit. He gave me the surprising news that my lungs would be virtually back to virgin health in 4-5 years (after nearly 10 years of smoking). And to get back to exercising more.
I smoked for 7 years, the quit, then picked it back up 4 years later for 5 more years. I didn't really meet the criteria outlined in this article of x "pack years and over 55". I have read that quitting before 40 reduces your chances of lung cancer to that of the general population. Honestly within two years it was stark how much a difference there was.