Camille filed for divorce from Kelsey in 2010 after 12 years of marriage amid rumors that Kelsey cheated on her with producer Kayte Walsh, whom he later married. The estranged couple share two children together (14-year-old daughter Mason and 11-year-old son Jude) both born via surrogate.
Their lack of communication could be affecting the way they're raising their kids.
"It's impossible to co-parent because I have to go through second and third parties," Camille said. "I have to call an assistant to call his bookkeeper to get back to me. It would be amazing if we could just communicate, but he refuses to."
Kelsey was unavailable when ET reached out for comment.
Camille says not even her cancer diagnosis was able to break down the wall of silence.
"This is his choice and I can't change his mind," said Camille, who admitted that she wished Kelsey had been more present during her battle with endometrial cancer, which attacks the lining of the uterus.
The former Real Housewives of Beverly Hills star underwent a radical hysterectomy in 2013 following her diagnosis, and she assured us that today she is in "full remission" and has been for nearly two years. Her current state is a far cry from where she was at the time of her diagnosis, which she described as "surreal."
"For that moment, it takes your breath away," Camille said. "Then you just compose yourself and go, 'OK. And what do I do next? What do I need to do next?' Because I want to beat this. I need to survive this for my children."
Camille is now turning the lowest period of her life into a positive, using her experience with battling cancer to help others. She was named this year's chair of the National Race to End Women's Cancer this weekend in Washington, D.C.
Click here to donate to her cancer awareness cause and join her team of Camille's Crusaders.