O.J. Simpson

Things get worse—MUCH WORSE—for creepy double murder acquitee O.J. SIMPSON.

O.J. is heart­broken – his beloved sister Shirley is desper­ately fighting for her life against breast cancer and he can’t be there for her, The ENQUIRER has learned.

“Shirley is not doing well,” revealed a source close to O.J.’s 68-year-old sister.

“This is her second go-around with breast cancer, and it’s come back with a vengeance. It’s spread throughout her body.”

O.J. is weeping in his Nevada prison cell for his sister – who stood steadfastly by him during his headline-making trials.

Shirley – who lives in San Francisco with her husband Benny Baker, a retired bus driver – is putting her faith in God.

“Yes, I DO have breast cancer,” she confirmed in an exclusive interview.

“I’ve been in touch with my brother (in prison), and he knows about it.

The imprisoned footballer, 64, “has always been close to Shirley,” the source said.

“She has always refused to be­lieve that he killed his ex-wife Nicole Brown and waiter Ron Goldman."

ALL the details are in the newest ENQUIRER – on sale NOW!