I've had to deal with many people who don't really want to do what it takes to be healthy for 15 years now. So in answering your "real question", all I can say is you can lead the horse to water, but you can't make it drink. I've learned you have to respect their wishes and desires and be there to help them die if need be.
The best solution to all that is to find something that will help them pretty fast, where they will see improvement within 2-4 weeks, and that will cause them to try more. No one wants to feel bad.
As for the lung cancer, I'm into ozone. I had a friend's wife who had stage 3 or 4 lung cancer last year. She started doing ozone, and that was the only time the cancer didn't advance. But I think she did too much and spit up some blood and quit, and then went the conventional route and died last Dec right after Thanksgiving. I can explain ozone more if you're interested.
Forgot to mention you're totally right about diet too. That's really important! And there is the Food Revolution Summit starting up today, where you can join for free and listen to a lot of experts in the field. It's supposed to focus on diets for cancer too, but not so sure about that. http://foodrevolutionsummit.org/truth-about-cancer/