After a successful round of chemotherapy treatments over the summer for Stage 4 pancreatic cancer, Jeopardy! host Alex Trebek has announced he will require additional treatments.

"It appears I will be having more chemo treatments ahead of me," the host announced Tuesday on his YouTube channel. "One of the things I've learned in the past six months is that the course of pancreatic cancer treatment is not always a straightforward affair. There are always curves and unexpected events."

"This past summer, because I was making such good progress, we thought I was finished with chemo," Trebek continued. "That was a bit premature, and certainly overoptimistic. I began immunotherapy, but that didn't go very well at all. My numbers went south, dramatically and quickly."

Trebek said the doctors are "reexamining" his situation. He had initially revealed his diagnosis in March, and followed up in May stating that the cancer was in a state of near remission. Trebek has returned to host Jeopardy! for its current 36th season.

RELATED: Alex Trebek Completes Chemotherapy, Returns to Jeopardy!

Despite the setback, Trebek concluded his announcement with a show of optimism. "Hey, [the treatments] worked very well the first time, so we're expecting good results again."

"But please keep me in your good thoughts and prayers," Trebek added. "Believe me, it means a lot."

Jeopardy! airs nightly on NBC.

(Via Deadline)