In a July 20 video posted on the group's Web site, Adam "MCA" Yauch of Beastie Boys stated that the rock-rap crew is cancelling its upcoming tour dates and postponing the release of its new album while he undergoes treatment for cancer, including urgent surgery.

Yauch was diagnosed last week with a tumor in his left salivary gland. Because it was diagnosed early enough, it is treatable, and his vocal chords will not be affected.

"I just need to take a little time to get this in check, and then we'll release the record and play some shows," Yauch said in the video. "It's a pain in the neck (sorry had to say it) because I was really looking forward to playing these shows, but the doctors have made it clear that this is not the kind of thing that can be put aside to deal with later."

Affected shows include All Points West (July 31) in Jersey City, NJ; Osheaga Music & Arts Festival (August 2) in Montreal, QC; Congress Theater (August 6) in Chicago, IL; Lollapalooza (August 8) in Chicago, IL; Outside Lands Music & Arts Festival (August 30) in San Francisco, CA; Hollywood Bowl (September 24) in Hollywood, CA; and Austin City Limits Festival (October 2) in Austin, TX.

Beastie Boys were headlining the five aforementioned music festivals. Festival promoters are currently looking for replacement headliners. Refunds will be available at the point of purchase, where applicable.

The September 15 release of their new album, "Hot Sauce Committee, Pt. 1," has now been pushed back to an undermined date.