Tahitijin,
Welcome, we are just sorry for your Dad's reason for being here. He is fortunate you are here for him as an advocate. Yes, lymph node involvement and probable stage 4 is serious. With kidney involvement, you need a real team that can put all of the urinary tract under response. None of us are doctors so I couldn't even begin to guess what all needs to be done. I'd get to a major cancer center such as MD Anderson, Sloan Kettering, Stanford etc if possible. You mentioned immunotherapy. Perhaps one of those major centers will have something new or better, BCG/immunotherapy is usually done with non invasive bladder cancer but, perhaps that in conjunction with something else? There will be people here listening and will try to answer questions as they come up. You are already supporting him by trying to get answers here. As I have learned with parents that have passed a few years back, loving them is the best thing you can do!