In a posting on the band's website, Yauch reveals a cancerous tumour in his left salivary gland will need surgery. He is expected to recover fully.
"I just need a little time to get this in check and then we'll release the record and play some shows," he wrote.
Hot Sauce Committee Part I was due to be released on 15 September.
The band had been due to play a number of headlining slots at festivals across the US, including the Lollapalooza event.
One of the act's last live performances was at Tennessee's Bonnaroo music festival last month.
* Story taken from BBC Entertainment News, 20/07/2009