My father was diagnosed with stage 4 lung cancer in August 2005 (around the same time Dana Reeve was diagnosed). It has been eight months and I spoke with my father toady and I asked him how he is doing and he replied 'I am really feeling great!' I strongly encourage you to get second opinions and to look into clinical trials. My father started out on a clinical trial and his cancer has not spread...he is stabalized for now.
Read everything you can...go to all the doctor visits ... ask questions, take notes. I found that this really helped my parents because it is all so very emotional.
Greg Anderson a man who was diagnosed with stage 4 lung cancer and has beaten it has written some great books. Hope is so very important. People do beat lung cancer...why not your father and my father.
Good luck to you and your family ... I know that it is so very hard ... You are in my prayers.