Def Leppard guitarist Vivian Campbell has gone through some highs and lows in his cancer battle over the last couple of years. There was a period where he thought his cancer had passed, but it returned. He also went through a stem cell transplant, feeling that was his best option to keep it from returning the second time around, but it has returned once again. In a new interview with the Salt Lake Tribune, Campbell addresses his current health status.

"The bad news is it keeps coming back," said Campbell. "The good news is the treatment I'm doing largely continues to work, which is a big, big part of the recovery for me, to be able to continue to do what it is that defines who I am. I've had a couple rounds of chemo — actually, three rounds of chemo. And last October I did a stem cell transplant. And I kind of naively thought that'd be it, and I was done with it. I guess given the benefit now of my experiences with this, I kinda realize that I'll probably be dealing with it for the rest of my life. So we're trying a new track now."

He adds, "I'm trying a process called immunotherapy, which is the latest and greatest thinking in how to treat cancer. So, it's part of a clinical trial, and it's early days yet, so I really won't know until the end of the year, I won't really have an idea about the efficacy of this treatment. The good news is it allows me to continue to tour, because I just have to do these infusions every three weeks or so. It's a bit of a pain because I have to travel back to Los Angeles. But as far as side effects, there's absolutely nothing that's of any concern -- it's just lowered my thyroid considerably. But if that's the only side effect, I'll certainly take it. It's a lot easier to deal with than doing chemo."

Because of his treatment, Campbell says he wasn't all that involved in the recording of the band's upcoming self-titled album. But even though he was absent for a good portion, he states, "I'm the new guy in Def Leppard, I've been in the band for 23 years, and I'll say that in the 23 years, I think this is the best record we've made -- that's point number one; point number two is I've have had very, very little to do with it! [Laughs] So I think the universe is trying to tell me something, you know? That they're creatively better off without me."

The guitarist revealed that the band recorded the album in three installments and he missed the middle portion. "Each was between four and six weeks," says Campbell. "I was there for the first one and I was there for the last one, and I missed the middle, which, to be honest, is probably where all the hard work happened."

Look for Def Leppard's self-titled album, arriving in stores Oct. 30.

See Where Vivian Campbell Ranks on Our List of the Top 50 Hard Rock + Metal Guitarists

Watch Def Leppard and Others in Our 'Monsters of Rock' 8-Bit Video Game Trailer