Though I imagine that the original poster has exhausted all his standard treatment options, it might also be worth mentioning the sort of 'precision medicine' that major cancer centres like Sloan-Kettering are now starting to do. The idea is to take a sample of the tumour and sequence all the genes in which mutations might make the cancer responsive to some specific treatment (perhaps a drug that would not normally be considered for that type of tumour). This can now be done very rapidly. If one of the genes comes up as positive for an 'actionable' mutation, then in some circumstances the patient may be offered a treatment that is intended to exploit the damaged gene to target the tumour (e.g., as part of a new type of clinical trial that runs across cancers of different types where individual cases happen to have mutations in the same gene). Further details, including contact information, are here:
My best wishes to the poster and his family at this very difficult time.