Alex Trebek is treating his 'Jeopardy!' hosting duties as ''just another day at the office'', despite battling stage four pancreatic cancer.

The 79-year-old TV star announced his cancer diagnosis in March, and after undergoing chemotherapy, he returned to host the 36th season of his popular US game show earlier this month.

But Alex insists he isn't treating the new season of the show any differently despite it marking his first season since fighting cancer.

During an appearance on 'Good Morning America', the star was asked how season 36 feels for him in light of his diagnosis, and he said: ''[It's] the season that comes before number 37. That's it. It's another day at the office. But what a wonderful office to go to do your work.

''As long as I can walk out, and walking out is more of an effort now than it used to be, as long as I can walk out, and greet the audience and the contestants, and run the game, I'm happy.''

Alex's optimism comes after he recently revealed he is undergoing more chemotherapy treatment, as although he was nearing remission in May, he was told in a recent doctor's appointment that his ''numbers [are] sky high'', so he needs to resume the treatment.

He said: ''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 gonna stop chemo, we'll start you on immunotherapy.'

''I lost about 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.''

The disease has taken its toll on the presenter's body as he's been suffering from ''excruciating pain'' and ''fatigue'' and also admitted he fell into depression when he was first diagnosed.

He added: ''When it happened early on I was down on myself.

''I didn't realise how fallible each of us is in his or her own way ... I talk to the audience sometimes and I get teary eyed for no reason. I don't even bother to explain it anymore, I just experience it.

''I know it's a part of who I am and I just keep going.''