Angel also shared photos of Johnny shirtless and hooked up to machines on his Instagram Story, writing, "Sad! ANGRY! But we WILL get through this."
Johnny's mom, Shaunyl Benson, shared similar shots on her Instagram account, captioning the photos with facts about childhood cancer.
"THIS is childhood cancer. THIS is happening right now. Every 2 minutes a child is diagnosed with cancer. 1 in 5 of those children will not make it," she wrote. "THIS is our son Johnny Crisstopher @crissangel he has battled for 3 years and has another 3 to go. He is only 5 years old. THIS has been his normal since he was 18 months old."
"Today he doesn’t even want to smile because the medications make him sad and angry," Benson continued. "It’s the day after Christmas and our day started early for a long round of chemo. Instead of planning our next year at school, we are planning our next hospital stay. THIS is happening right now."
In Angel's December statement to ET, he said that his family is "devastated by this unexpected news," but added that they "believe that he will be in remission again soon."
"He is an amazingly strong little boy, and with the support of family, friends, and my loyal fans we look forward to the day he is again in remission," the statement read in part. "We want to thank you all for the outpouring of love, good thoughts and prayers for our amazing boy."