The Jeopardy! host sat down for an interview with CBS Sunday Morning's Jane Pauley, where he discussed learning that he had stage-four pancreatic cancer, which involved his doctor finding a lump the size of a "small fist" in his abdomen.
The 78-year-old TV personality immediately went into treatment while somehow continuing to work, which meant enduring some excruciatingly painful days.
"This got really bad. I was on the floor writhing in pain... It went from a three to an 11. And I just couldn't believe. I didn't know what was happening," Trebek tells Pauley. "And it happened three or four times a day while we were taping. So that was a little...little rough on me."
However, despite the difficult days on set, Trebek shared that he didn't want to halt production if he could help it.
"I had 15 minutes before the next show," he recalls. "So I got myself together and spasms...usually last about 10 to 15 minutes. So, all right, here we go again. 'Anybody got any pain pills?' And I don't like taking pain pills. But...I got through it. And the producers were very kind. They said, 'Look, if you -- If you don't want to do the show, we'll just cancel taping.' I said, 'No. We're here. We're doing the shows.'"
Trebek also jokingly explained that he's betting fans are wondering if he still has his hair, or if it has already fallen out due to chemotherapy and he's now wearing a hairpiece.
He confirmed that he is indeed wearing a toupee, which he's hearing might look better than his own hair. But, over his summer break, he hopes to grow it back, adding, "'Cause I like my own hair."