Yesterday he revealed he is "starting aggressive treatment for the next few months to fight" the disease.
"So i have the news. It was a bit of a shock and i've got an interesting journey ahead and a bit of a battle. I am starting aggressive treatment for the next few months to fight the diagnosis of brain cancer. Please stay positive for me and ill try to update you guys on my progress."
"Some things in life really put things into perspective, hoping for a positive result, keep me in your thoughts x," Ruffo wrote on Instagram.
Stay strong Johnny!
This article originally appeared on In Style.