Adam Yauch, aka MCA, has been undergoing treatment since July 2009, when doctors found a tumor in his parotid gland.
He has also adopted a strict vegan diet and turned to ancient Chinese medicine to help him beat the disease, and although his prognosis is good, Adam Horovitz admits Beastie Boys is putting off any live dates following the release of "Hot Sauce Committee Part.2" until Yauch's back to full health.
Horovitz says, "He's doing OK. He's still in treatment, so it's not 100 per cent (clear). But things are looking good."
"We're not touring, we're just getting the record out - and we're not making any plans until he is better. Which is definitely going to happen."
But Horovitz is confident Yauch will be joining the group to make a full comeback soon - and he's sure they will bounce back harder than ever before when the time comes to record their next project.
He adds, "I have a feeling the next record is going to be the most insane party record you ever heard. Because if you go through something like what Yauch's going through, I mean, s**t. After that, you must feel pretty good."
Horovitz's comments come four months after band mate Mike D claimed Yauch had been given the all-clear, prompting the sick star to clarify the remarks and reveal his treatment is ongoing.