Politically, I’m not too wild about him, but I wish him well, and he certainly has been through the wringer in this lifetime.
My daughter-in-law died of this kind of brain tumor, which is the most common kind. Three months from diagnosis to death. She had radiation, but I think that was more of a “we can’t just do nothing!” response.
She had been a little “off” in the weeks prior to the diagnosis, but there was a lot of stuff going on, including a move across the country, and a new job in the family–everyone just assumed it was the stress of adjusting to a bunch of changes. This would certainly explain McCain’s somewhat incoherent speech at the Comey hearings.