I am sorry to read about your dad, Wii. I remember when he was going through this before, and how tough he was. The Tao Te Ching says, "we live until we die." Your dad is still alive and that is something to be joyful about. Who knows when his time will come. The doctors can't say for a certainty. Just enjoy your time with him. I know you will support whatever choice he makes. Often, chemo gets rid of all the cancer, at the bemusement of doctors, but there are those pesky odds. Just remember, your dad is not a statistic, and he is not date stamped.
Things I take to try and reduce my cancer (just a suggestion that you might like to get your dad to try): Vit. D3, lots of berries, veggies (the more colourful the better), organic foods, wild salmon; just came across the benefits of coconut oil for all kinds of ailments, so I have started eating it (everything cooked in it, and also things like coconut ice-cream, coconut milk, etc.). I am not looking for a cure, just to live longer like your dad. No-one gets out alive, anyway, but if you can go out comfortably, I'd say that that's a good thing.
You and your family are in my prayers.
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