The Cheech & Chong star was diagnosed with prostate cancer in 2012 and he shunned traditional treatment for alternative therapies. He was declared free of the disease a year later (13).

However, the 77 year old announced over the summer (15) that the cancer had returned, and he has now confirmed he is set for surgery.

Chong went public with the news while picking up an award at the Las Vegas Hempfest over the weekend (03-04Oct15), and he told the crowd the operation spells "good news".

"A couple of years ago I was going around the country bragging that I had beat my cancer with marijuana," he said. "Only trouble is: I don't know what kind of strains I used, but I used the kind of strain that the cancer said, 'Oh f**k I like this one'. And it came back, big-time. But I'm fighting it. I'm due in for an operation at the end of this month. By the way it's good news: I'm going to get a new a**hole..."

The funnyman went on to joke about America's upcoming presidential race and potential Republican candidate Donald Trump.

"I feel like the Republican Party with Trump...." he laughed. "The Republican Party and Tommy Chong have one thing in common: We're both having problems with their a**holes. I've got a tumour and the Republican Party has got Trump."