During an interview on "Good Morning America" Wednesday, the "Jeopardy!" host gave an update on his condition and discussed the unexpected challenges he's been facing.
"My oncologist tells me I'm doing well even though I don't always feel it," he says. "I've had kidney stones, I've had ruptured discs, so I'm used to dealing with pain – but what I'm not used to dealing with is the surges that come on suddenly of deep, deep sadness and it brings tears to my eyes."
He also says his fans' thoughts and prayers have made a positive difference in his journey.
"People all over America have been sharing their good thoughts, their advice, their prayers," he said. "And I feel it is making a difference in my well-being."