The latest story indicates that he and the GOP(e) are hoping he holds onto his seat until 2022 (good grief) ....
He might. Mrs. Liberty has a Nephew who had Glioblastoma, and he
beat it (through the VA no less!). We really thought he was a goner, but he's back to teaching riflery in the Marines at Quantico. He was literally the "tip of the spear" in Iraq. She also has a Niece with Stage 4 cancer, and she beat that into remission too. Granted, they're both decades younger, with no previous cancers.
McStain has the best medical care a US Senator can buy.