Megadeth have canceled many of their upcoming shows following the frontman’s revelation on Instagram.

“I’ve been diagnosed with throat cancer,” Dave Mustaine wrote. “It’s clearly something to be respected and faced head on — but I’ve faced obstacles before. I’m working closely with my doctors, and we’ve mapped out a treatment plan which they feel has a 90 percent success rate. Treatment has already begun.”

“Unfortunately, this requires that we cancel most shows this year. The 2019 Megacruise will happen, and the band will be a part of it in some form. All up to date information will be at megadeth.com as we get it. Megadeth will be back on the road ASAP.”

Megadeth’s tour schedule for 2019 mixed festival dates across the U.S. — including Milwaukee’s Summerfest and Psycho Las Vegas — with a few shows with Ozzy Osbourne. They also had a handful of gigs in South America scheduled for September. The band’s Megacruise is slated for Oct. 13-18 this year.

Mustaine added that, even though they’ve been forced off the road, the other band members will continue to work as he receives treatment.

“Meanwhile, Kiko, David, Dirk and I are in the studio, working on the follow-up to Dystopia – which I can’t wait for everyone to hear,” he concluded. “I’m so thankful for my whole team – family, doctors, band members, trainers and more. I’ll keep everyone posted.”