Alex Trebek is undergoing more chemotherapy.

Alex Trebek

Alex Trebek

The 79-year-old TV star was diagnosed with stage four pancreatic cancer in March, and after announcing in May he was nearing remission, he returned to work on 'Jeopardy!' a few weeks ago.

Sadly, although Alex was doing "so well", doctors decided to stop chemotherapy, recent tests have discovered his "numbers [are] sky high" so he needs to resume the treatment.

Speaking on 'Good Morning America', 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 said: "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."

Alex insist the thought of death doesn't "frighten" him because he's had a long and "good" life, but he does get upset at the idea of how it will affect his family and friends.

He said: "I realise that there is an end in sight for me, just as there is for everyone else. One line that I have used with our staff in recent weeks and months is that when I do pass on, one thing they will not say at my funeral is, 'Oh, he was taken from us too soon.'

"Hey guys. I'm 79 years old. I've had one hell of a good life. And I've enjoyed it ... the thought of passing on doesn't frighten me, it doesn't.

"Other things do, the affect it will have on my loved ones ... it makes me sad. But the thought of myself moving on, hey folks, it comes with the territory."

Despite his latest health set back, the veteran host has no plans to stop working.

He said: "As long as I can walk out and greet the audience and the contestants and run the game I'm happy."