Don't listen to anyone time. It all depends on the person, the exact stage the cancer is in and the persons outlook on it. My mom was diagnosed with stage 4 breast cancer in May of 2005. They expected her to be around a few weeks. She's still here. She has some really really bad days and is in pain a lot but she's still here. Her doc. says it's all because she keeps a positive outlook on it. She refuses to give up plus, she has her whole family, friends, and strangers supporting her and praying for her.
You do need to spend time with him and be there for him. Help him out. Just talk to him and let him know you are there for him. I'll keep you in my thoughts and I wish you the best. If you ever want to talk, vent, cry, yell, whatever then e-mail me.