LEON Spinks, the heavyweight boxer who famously shocked Muhammad Ali in 1978, is battling prostate cancer that has spread to his bladder.

His wife has confirmed the news about the 66-year-old, who was first diagnosed in May.

“It’s going to be a long road and a lot of work,” Brenda Spinks said in a statement to USA TODAY Sports. ‘But we are bound and determined for the Champ to make a comeback!’

According to the U.S. publication, Spinks is now back at his family home in Nevada, after being discharged from hospital in Las Vegas in New Year’s Eve.

Back in December, she revealed on Facebook that Spinks was struggling with his health.

”Dear Friends,” she wrote. “I know it’s been a while. However, you know how I believe in the power of prayer. It’s been a tough year for us. Leon has endured a lot of medical problems. I’m reaching out to ask you to kindly pray for my beautiful husband Leon (so that) he may overcome the obstacles that have crossed his path.”

A member of the Nevada Boxing Hall of Fame, Spinks is best remembered for upsetting Muhammad Ali in 1978 to win the heavyweight title on a points-decision.

Ali won their rematch later that year, marking his final victory in the ring. Speaking to The Guardian in 2005, Spinks rejected claims that too much partying following his initial victory contributed to his defeat in the rematch. 

He was even arrested between fights for possession of cocaine that was found in his hat.

“That wasn’t me, somebody who was wearing that hat put it in there,” Spinks said. I don’t know if it was a friend or whomever. A lot of people tried my hat on.

“I wasn’t out of shape for the fight. Yes, I put on some weight, but you can see that I was in shape. How can you be out of shape?

“I went 30 rounds with the man … I think I won the second fight as well. But they wanted Ali (to win).

“It’s politics. It ain’t what you know but who you know.” 

Throughout his career, Spinks won 26 fights out of 46 and also won Olympic gold in the 1976 Montreal Games. He lost 17 and drew three.

Prior to becoming heavyweight champion, Spinks served in the U.S. Marines for three years.

In 2006, it emerged that Spinks was working as a janitor in Nebraska for $5.15 (£3.93) an hour at a local convenience store and a McDonald’s.

“I unload the delivery trucks when they come in and get 50 per cent off on Big Macs,” he told the Sunday Times.

Spinks has struggled with poor health in recent years. He was previously hospitalised in 2014 after chicken bones caused significant damage to his intestines, according to TMZ. He subsequently endured numerous surgeries.

His brother Michael was also a professional boxer who was beaten by Mike Tyson in the first round of their fight in 1988 and his son, Cory, was welterweight champion from 2003 until 2005.

Another of his sons, Leon Calvin, was killed in 1990 in a drive-by shooting.