Talk to him. And not about the cancer. But about life. Listen to him. Most people want to just be heard. Ask questions about dealing with family, life, and focus on good times. Talk about his hobbies---fishing, cars, etc. and maybe in his honor, take it up. learn from him. You'd be surprise how people feel to NOT have to focus on their illness and be treated like a normal human being instead of a pity-case.