I'm sorry to hear about your dad. Any cancer is terrible, and I know from first hand experience, watching both my mom and dad die of cancer. What I can tell you now is to get ready for a fight. Your dad has to fight for his life, not just wait for the inevitable. You, his family, his friends, all have to be in it together. My dad was diagnosed with brain cancer in 2001. He was only supposed to have about a year to live, but he lived for four, because until the end, neither he nor my mom ever gave up.
We had pretty terrible experiences dealing with the doctors, even though it was supposed to be one of the country's best hospitals (Stanford - it sucks). You'll need to push for everything you can. If you think your dad needs to get an MRI, but the doctors want to wait, do not let them. With cancer, a lot can happen in a month or two - time is invaluable. If you can get second opinions, do it. Different doctors see things differently, and it's important to get more feedback. Maybe you'll find a better doctor, while you're at it. The problem with a lot of oncologists is that to them, your dad is just another case (this is not true for ALL doctors, btw, unless you're at Stanford Hospital). They know the odds, and they know what the text books say. But your father isn't their father. Don't expect doctors to fight for his life - all they're doing is treating him.
Do your research. There's support groups, tons of online resources, medical journals... Support groups can really help, not just for emotional support, but for information. They can provide tons of info on treatments, alternative treatments, drugs, nutrition, etc. If you have any friends or family in the medical field, including the drug industry, or pharmacies, don't hesitate to ask them for advice.
Here are a couple links you ought to read. The first is about a drug called DCA. It's not proven, but hey, with almost no side effects, it won't hurt. Find a way to get your hands on it:
http://www.cbc.ca/canada/edmonton/st...cer-chemo.html
This one's about cancer fighting foods. Diet is pretty important. Not just for cancer fighting potential, but for overall physical and mental strength:
http://www.thedietchannel.com/Cancer...ting-Foods.htm
Good luck. I hope your dad can live much longer than five years. But either way, enjoy whatever time you have left with him. Make him laugh, and go out and do things together. A healthy mental spirit is one of the best treatments for any disease, and you don't want to regret not spending enough time with him.