Sad news. Unfortunately it sounds like the form of cancer he is being diagnosed with is very aggressive, and has a low survival rate even for younger individuals. I can't imagine he holds on to the seat much longer, the time would be better spent with his friends and family.

After his questioning during the Comey hearing I made a post questioning whether his age had become a liability in his duties, sadly it seems to be much worse than that.

I hope he can beat this, but it seems unlikely.