(CNN) "Jeopardy" host Alex Trebek is hoping for a victory as he wages a battle against cancer.

The longtime game show host on Wednesday announced he's been diagnosed with stage 4 pancreatic cancer in a video posted to the show's official YouTube account.

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

Pancreatic cancer, on average and across all stages, has a 5-year survival rate of 9%, according to the American Cancer Society.

Trebek, 78, has hosted "Jeopardy" since 1984, when the show began airing daily in syndication.

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