Olivia Newton-John sent a message of support to Alex Trebek after he was diagnosed with stage 4 pancreatic cancer.

Olivia Newton-John

Olivia Newton-John

The 'Grease' star is currently battling cancer herself for the third time, and says she contacted the 'Jeopardy!' host to tell him she knows he "can get through this" after he candidly spoke about his diagnoses in a video message to his fans earlier this month.

Speaking to 'Entertainment Tonight', she said: "I sent him a message saying, 'I know you can get through this,' and, 'Don't listen to stage four and all of [that]. Don't read the statistics and stay focused and see how you can heal yourself.'

"That helps. Sense of humour is vital. He has a great attitude and a great sense of humour about it and I'm sure he'll do very well."

Olivia's comments come after the 78-year-old television presenter admitted he is aware that the prognosis for the disease is "not encouraging", but he's vowed to "fight" it and will continue working on his game show.

In his video message, Alex said: Hi everyone, I have some news to share with all of you. And it's in keeping with my longtime policy of being open and transparent with our Jeopardy fanbase. I also wanted to prevent you from reading or hearing some overblown or inaccurate reports regarding my health.

"So therefore, I wanted to be the one to pass along this information. Now, just like 50,000 other people in the United States each year, this week I was diagnosed with stage 4 pancreatic cancer.

"Now normally the prognosis for this is not very encouraging, but I'm going to fight this and I'm going to keep working."

Alex - who has children Matthew, 29, and Emily, 27, with wife Jean Currivan - then asked fans to pray for him to beat the disease.

He continued: "And with the love and support of my family and friends, and with the help of your prayers also, I plan to beat the low survival rate statistics for this disease."

And Alex joked he has to keep working because of the terms of his contract on the game show, which he has hosted for 35 years.

He quipped: "Truth told, I have to because under the terms of my contract, I have to host Jeopardy! for three more years! So help me!

"Keep the faith and we'll win. We'll get it done. Thank you."