I'm so sorry to hear about your Dad and I have just prayed for both of you this very moment...that God will wrap His loving arms around you both and that by reaching out to others, you will find the help for your Dad.
I would suggest that you contact M.D. Anderson in Houston 713-792-6161. They handle the most unusual and desperate cases of cancer in the world. They treated me for metastatic cancer in both lungs for the past year...8 months of chemo and two surgeries. i am now cancer free and I feel great. I was considered stage IV, so there is always hope. Make sure you let your Dad know, and inspire him, to hope and to have faith. His attitude is very, very important for his healing...not to mention his day to day living.
I will keep you in my prayers and please let your Dad know that there are people he doesn't even know who are praying for him at this very moment. There is great power in prayer!