You're right. Outlook is not good. Went through it with my mother. It was the metastasized breast cancer. I did a lot of internet research and knew it was coming and think it helped me process the death before it happened. Other family members were in denial and the impact was much more severe to them once she passed. If I personally was talking to someone about to go through what I did, I would suggest seeing a therapist throughout to process what is going on. I did and am glad I did. I cried a lot in there but it helped me process. Like I said some family members didn't and I can't help but think it would have helped them tremendously. Just be there for your friend if he wants to talk about it or if he doesn't. I got very tired of talking about it that I avoided people to not have to talk about it. It will be on his mind with every conversation, interaction he has.
I never understood people giving food for people in tough times until I went through this and realized between all the trips to the pharmacy, doctors and with care giving no one has time to cook or even get take out. Dad lost a lot of weight, he was too exhausted to remember to eat. Perhaps organize people giving prepared meals when things progress and your friends days are filled with the care giving.
With my mom they found the lesions in her spine first when she complained of back pai n after 17 years in remission. The doctor said the longest they had seem someone live from that stage was 2 years. My mom made it 4. Once we knew it was in her brain stem the doctors said they were stopping treatment. It was heartbreaking to see someone hear that news when they wanted to keep fighting. My mom passed away within 4 months of them finding it in her brain. Over the 4 years she fought like hell and tried every cancer fighting drug available, was part of many drug studies, had blood transfusions, took bone strengthening meds. She did radiation and chemo. Some of the drugs that were in study stage when she tried them have now passed so I hope these drugs improve the outlook.
Going through it all it was comforting to know people I did not expect to care did care. So touching to see who all came to the funeral to provide support. People are amazing. A group of friends sent a gift basket full of tea, cheese, snacks, chocolate to me with a thoughtful thinking of you card. That was very comforting. We didn't necessarily sit down and enjoy the basket, more so had snacks and comfort food when we were on the run. I was so touched by the unexpected gesture.
I think responding to this may have helped me too. I am a reddit lurker, not a poster but feel like I was meant to come across this post and respond. You are a good friend! Just keep doing what you're doing.