I'm sure this isn't news but the first thing he will probably be told is to give up smoking ASAP. My mum has been told she has COPD as well as lung cancer but her consultant basically said it's another term for emphysema which is commonly foun in long-term smokers.
I suggest you ask all the usual questions - short and long term health effects, both with and without giving up smoking. What treatments are recommended and available - both conventional and complementary/alternative.
I would also ask why they wrote a diagnosis on his chart without telling him first. That seems highly unprofessional.