Hi Mark,
I don't want to intrude - now, or any time, as you are going through the coming time with your son. There is no 'right' thing to say, so I will try to keep it to a minimum.
Any time you would like to share an update on him; he had a good/bad day, he felt well enough for us to go drop a line for some spring Chinook, or whatever--or if you would just like a sounding board to share how fucking unfair this is--I am your friend, and I'm here for you.
I usually say too much, under the best of circumstances, to I'll leave it here. Please give my best to Andy; I love you both.
Michael