Oh, I am so sorry to read about your H's dad. I said a prayer for him.
May I suggest a book that helped me a lot with my cancer - Cancer 50 Essential Things To Do 3e - Paperback (Feb 24 2009) by Greg Anderson and Carl Simonton
It helped me a lot even though I didn't follow all of the advice. I gave it to my friend's sil, and she had a bad prognosis, more than a year ago. She followed more of the advice and still going strong. Tell your H, the C word isn't a death penalty, and not to put a time limit on his dad's life, or anyone else for that matter, healthy or not.
Take care.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim