Transcript for Alex Trebek returns to 'Jeopardy' after sharing cancer diagnosis
your rheumatologist about Xeljanz xr. Finally tonight, here what is the determination? Tonight, Alex trebek doing exactly what he said he would do. He has returned to work. Back on the job, just a week after revealing his cancer diagnosis. Stage four pancreatic cancer. He vows to beat the odds. Tackling it, as we all heard, with his trademark wit. With the help of your prayers also, I plan to beat the low survival rate statistics for this disease. Truth told, I have to, because under the terms of my contract, I have to host "Jeopardy" for three more years! Reporter: Trebek, who is 78, has been the host of jeopardy for 35 seasons. This was his first night. Alex trebek! Reporter: 34 emmys. Tonight, what he told "People" magazine just weeks ago. About his wife Jean, together 29 years. He said he wishes he met her earlier, asking for even longer life together. Those words now even more poignant, with this new battle, and with so many of you at home pulling for him. Trebek, tonight, back at work. We're all rooting for Alex. I'm David Muir. I hope to see Your brain is an amazing thing.
This transcript has been automatically generated and may not be 100% accurate.