Hellion,
I want to suggest that you consider looking at the clinical trials going on at NIH. There are immunotherapy trials for metastatic cancer like:
https://clinicaltrials.gov/ct2/show/NCT01967823?term=NIH+immunotherapy&rank=6There are also
HPV immunotherapy trials going on too:
https://clinicaltrials.gov/ct2/show/NCT01585428?term=NIH+immunotherapy&rank=3Another thought is to have your tumor sequenced and find out what the mutations are and then choose a drug or clinical trial that targets your tumor's particular mutation. We paid for the cost of this sequencing out of pocket as insurance won't cover it. It ran about $5k and the outfit we used was Foundation One.
I have a friend who has metastatic melanoma and was given 3-6mos to live and is still going at 4.5yrs. There is still cancer there but he's stable and enjoying life. And I read about people in the Washington Post who are clean. They did these NIH immunotherapy trials and were lucky.
Good Luck.