There are certainly a lot more things to try. Don't give up hope. Since you didn't say how your dad is feeling it's hard to offer suggestions. I can tell you that my dad was dx 11/07 and was not a candidate for surgery. He's done 5-fu & radiation and gemzar. He's recently started Tarceva and oxyplatin. Prior to this last protocal he was sent home to die. He was in the hospital and the CT scan showed that the cancer was very aggressive and had met to lungs. We moved my parents closer to family and founda new oncologist. My dad was feeling very bad...couldn't walk, could barely talk because he would get out of breath and his stomach was very distended. He was also very depressed and did nothing all day but sleep or lay there with his eyes closed. He just had a CT scan after undergoing this new protocol and the cancer had not spread any more. He looks 100% better than when they sent him home to die. He's not feeling well but he's so much better. He can walk a little and occasionally watches TV and can carry on a conversation. He's even gone out to eat.
The current oncologist has been very frank with us. He says the odds are against us but continuing treatment is not going to make him feel any worse than he already feels. The hope is that it will shrink the cancer and stop it from spreading.
So don't give up hope. My prayers are with you and your family. You came to the right place to get support and advice.