Alex Trebek knows the end is coming, but that doesn't make it any easier.
Trebek went on to describe his perfect ending to his run, "What I would do on that day is tell the director, 'Time the show down to leave me 30 seconds at the end. That's all I want.' And I will say my goodbyes and I will tell people, 'Don't ask me who's going to replace me because I have no say whatsoever. But I'm sure that if you give them the same love and attention and respect that you have shown me... then they will be a success and the show will continue being a success. And until we meet again, God bless you and goodbye."
https://www.youtube.com/watch?v=CZLhIVnVV8k
Trebek revealed his diagnosis with pancreatic cancer last March. Though his cancer was in "near remission" earlier in the year, this past September there was a resurgence in the disease.
There is currently no publicly known date for Trebek's exit from the show.