I don't have much to say except I'm sorry to hear the news, but whatever happens, whatever any doctor says, simply show your dad love. I can imagine that he is going to want to have good times with his family if it is indeed terminal. Don't constantly keep the idea of the cancer beating him in your head though. Have a clear mind and simply enjoy the time you get to spend with your father. If it proves to be beatable, then that's more time you get.
I wouldn't want my family spending insane amounts of money on me, worrying about my survival, if I had terminal cancer. If it was a good prognosis, then yes I want to live, but if I have led a good life, I'd rather share some good enjoyable time with my family.
The James Cancer Hospital at The Ohio State University is ranked at the #15 hospital for cancer treatments. There comes a point where being the top doesn't matter, and good doctors will possibly refer you to places with better treatment capabilities if they don't have the resources for proper treatment of the specific cancer.
Oh, and suggest to your dad to toke up. THC has been researched and discoveries have been made (a few years ago even, and I can look up the articles again if you do indeed want them), that detail THC as having anti-tumor properties. Of course, nothing is guaranteed.. and it was researched in rats, not humans. And it's mostly hormone-controlled organs and tissues that received the beneficial effects, and it was over a 2 year period the individual rats were monitored. It's something I'd definitely take up if I were dying and had only a few possible treatment options. I'm not sure if the colon and liver are under hormonal control at all or not... so I don't know if the THC could do anything, or if it even does anything in humans. But, a chance is a chance, right?
And if he does receive treatment by means of radiation & chemo, he can be a candidate to be prescribed Marinol... it's a pill that contains THC (synthesized to 99% purity). It's meant for nausea and trouble eating, side effects of chemotherapy. But still provides that THC, which if taken over a 2-year period (not sure if you can continue to take it for 2 years straight, daily... could be hard getting that kind of lengthy prescription), could still produce the possible results you'd be looking for.