In an interview with TMZ, Angel said that Johnny, 5, will be going back to the hospital for treatment following a brief remission. He was first diagnosed with acute lymphoblastic leukemia in 2015.
"Johnny Crisstopher -- he got diagnosed with pediatric cancer before he was 2-years-old -- he’s been in treatment for over three years, he’s been in remission," Angel, 51, told the outlet. "But unfortunately ... he had a relapse and he’s going back into the hospital on Monday."
Before his son returns to the hospital, Angel said the family has been taking Johnny to theme parks in southern California.
"That’s why we’re partly out here in California," Angel explained, "because we take Johnny to Disney[land], I’m taking him to Universal [Studios] tomorrow."
The Las Vegas and Broadway performer said he will host an event at Planet Hollywood -- where his "Mindfreak" show is taking place next year -- to raise $5 million for children battling pediatric cancer. Angel also asked the public for their support when details are announced.
"We just want to thank everybody for their support over the years,” he told TMZ. “We want to try and raise five million bucks, so we need your help."