Pat Sajak, of "Wheel of Fortune," posted a statement on Twitter saying that he and his family are "saddened" by the news.
"Our hearts go out to him and his family," the statement read. "But there is no one I know who is stronger and more determined, and I would never bet against him. We, and the entire country, are pulling for you, Alex."
The Sajak family is deeply saddened to hear of Alex Trebek’s struggle with cancer. Our hearts go out to him and his family. But there is no one I know who is stronger and more determined, and I would never bet against him. We, and the entire country, are pulling for you, Alex.— Pat Sajak (@patsajak) March 6, 2019
Famed "Jeopardy!" winner Ken Jennings offered his support to Trebek as well. "One thing I know for a fact: Alex is very aware of how much he means to millions of people, and how we will be pulling for him," he wrote in part. "I hope that’s a comfort."
One thing I know for a fact: Alex is very aware of how much he means to millions of people, and how we will be pulling for him...I hope that’s a comfort.— Ken Jennings (@KenJennings) March 6, 2019
Actor Ken Jeong tweeted that he's sending "all my love, thoughts and prayers" to Trebek.
Sending all my love, thoughts and prayers to Alex Trebek.— Ken Jeong (@kenjeong) March 6, 2019
You are my hero. ❤️❤️??pic.twitter.com/CcXhVtqUT8
Chris Harrison, host of "The Bachelor," offered his prayers as well, from one host to another.
Thinking and praying for fellow game show host and absolute legend Alex Trebek as he starts his fight with pancreatic cancer. God’s speed my friend https://t.co/W0JJnlS6LY— Chris Harrison (@chrisbharrison) March 6, 2019
Dr. Mehmet Oz urged Trebek to "stay strong."
I'm saddened to hear about Alex Trebek's stage 4 pancreatic cancer diagnosis. Stay strong, friend. ❤️ https://t.co/oi3RvVZVCQ— Dr. Mehmet Oz (@DrOz) March 6, 2019
Others chimed in to offer their words of encouragement.
Robin & I are sending all of our love and prayers to Alex Trebek. He’s one strong guy and will fight this! https://t.co/nXy41nxaZT— Dr. Phil (@DrPhil) March 6, 2019
We are all pulling for Alex Trebek who just revealed he has stage 4 pancreatic cancer. He vows to fight this and to keep working. We're with you, Alex.— David Muir (@DavidMuir) March 6, 2019
I just want to say to Alex Trebek I know you can kick cancers ass. You are the true daily double and the ultimate Jeopardy! champion in my eyes.— Dane Cook (@DaneCook) March 6, 2019
Lots of positive energy coming your way from so many sir.
Sending best wishes to Alex Trebek, aka Alex Lebek, host of RiddleQuest pic.twitter.com/1CYARVlsil— Arthur Read (@arthurpbs) March 6, 2019
Trebek announced the news himself in a video posted on YouTube.
In the video message, Trebek said he wanted the news about his health to come directly from him and wanted to be "open and transparent" with his viewers about his diagnosis. He said he received the news this week.
"Normally the prognosis for this is not very encouraging, but I am going to fight this and keep working," Trebek triumphantly declared.