Black Sabbath have been on a huge roll the last couple of years. Their comeback album '13' is a Grammy-winning smash hit and they've been playing sold-out shows all across the world. But could the legendary metal band's touring career be coming to a close?

Guitarist Tony Iommi says in an interview with Metal Hammer that the last show on their summer tour could be their last show, period. That concert is at the Barclaycard British Summer Time Festival in London's Hyde Park on July 4.

"It could be the last ever Sabbath show,” Iommi says. “I don't want it to be, but there's nothing really planned touring-wise after that show, so for all we know that could be it really. To be honest I don't want to be touring to this extent too much longer, because it makes me feel so bad.”

Iommi has been battling lymphoma since early 2012. He finished up treatment in March, and is waiting for an update on how he's doing. "I'm at a stage now where I have no support, which means I have to see whether the cancer is coming back or if it's still there or what,” he says. “I just don't know. It's a bit of a worry. After we finish this tour I'll go in and have scan, so we'll see what that shows up.”

All Sabbath shows at this point in their career are special, but the Hyde Park gig will be even more so. Fans, of course, are hoping that Iommi gets a clean bill of health and that Sabbath are able to continue playing live for many years to come.