Transcript for 'Jeopardy!' host Alex Trebek shares new health update
surfer paddled back to shore. The latest on "Jeopardy" host Alex trebek sending a new message about his health after sharing that update here on "Gma" about his setback saying he needs to undergo another round of chemotherapy and T.J. Holmes has that for us. Anyone who has dealt with cancer, who has faced cancer, any family or friend who has had somebody face cancer knows there are incredible emotional highs and lows. Alex trebek is no different and, yes, this summer he got some positive news and he was excited to share that and you know what, just a couple of weeks ago he got some not so good news. That happens. The difference is he has chosen to share that as well with us. Exuding hopefulness and positivity since first revealing his cancer diagnosis in March, Alex trebek now says he may have been too hopeful about his early prognosis. One of the things I've learned in the past six months is that the course of pancreatic cancer treatment is not a straightforward affair. There are always curves and unexpected events. This past summer because I was making such good progress we thought I was finished with chemo. That was a bit premature and certainly overoptimistic. Reporter: Soon after revealing to us first on "Gma" yesterday that he'd experienced a setback in his cancer treatment, the longtime "Jeopardy" host released a new video message to his fans. The doctors are re-examining my situation and it appears I will be having more chemo treatments ahead of me. Hey, they worked very well the first time, so we're expecting good results again. Reporter: Trebek says doctors at one point described his cancer as near remission and he announced just last month that he was finished with chemotherapy treatment. I was doing so well and my numbers went down to the equivalent of a normal human being who does not have pancreatic cancer, so we were all very optimistic and they said, good, we're going to stop chemo and start you on immunotherapy. That doesn't work out well. I lost 12 pounds in a week and my numbers went sky high. Much higher than they were when I was first diagnosed. So the doctors have decided that I have to undergo chemo again and that's what I'm doing. Reporter: He is starting a new round of chemo just as he's kicking off a new season of this season's tournament of champions including James Holzhauer finding out about his diagnosis minutes before airing. It was hard to get psyched up to play some "Jeopardy" ten minutes later after we hear this. You know, it's great to see him out here again. He's such a consummate professional. It's like nothing's ever Announcer: Here is the host of "Jeopardy," Alex trebek. Reporter: No in his 36th season he contends nothing will be different. How do you go into this season any differently than previous seasons? How does season 36 for you now It's the season that comes before 37. That's it? That's it. It's another day at the office, but what a wonderful office to go to and do your work. As long as I can walk out and walking out is more of an effort now than it used to be but as long as I can walk out and greet the audience and the contestants and run the game, I'm happy. And it's no different than last year or the year before. And we talk about the inspiration he has been to people who are facing cancer. But get this, we touched base with several organizations. One of the leading pancreatic support organizations out there see an uptick in dough thags awareness and engagement. Every time a story like this airs about him, and, look, we don't have to get into the numbers about pancreatic cancer and survival rates. We know them but some say, you know what, he jumped the gun a little bit in sharing his good news. He's even saying it himself but who are any of us to tell this man how optimistic he should be about his future? So that sends a message. It's of value and it's paying some dividend, some actual tangible dividends but god bless him for what he's doing. Amen to that. An ABC exclusive.
This transcript has been automatically generated and may not be 100% accurate.