The 20-year-old, currently on-loan from Norwich City, released a statement confirming the news and will now take a break from football.
Barden has undergone follow up tests and will continue with a closely monitored treatment programme.
"It has been a very difficult and challenging period, but the support of my family, friends and colleagues has helped get me through the last few weeks," he told Norwich's website.
"I can't thank the medical departments at both Norwich and Livingston enough, as well as everyone at the Royal Marsden Hospital," the goalkeeper added.
“The speed at which everything has moved has been crazy, but everyone has been absolutely brilliant with me. Both Daniel Farke and the Livingston manager, David Martindale, have also been very supportive.
"The initial diagnosis was a real shock for me, but the positive thing is that we've caught it early and the prognosis and next steps have all been positive.
"I'm optimistic and have a positive mindset. I'm confident that I'll be able to beat it and that I'll be back out there doing what I love soon.
"I'd like to thank everyone around me for their support. I know that the coming period will be challenging and would ask for privacy for me and my family at this stage. Where possible, I'll do what I can to update on my progress."
Barden has featured once for Livi since his move.
Livingston said: “It goes without saying but we give Dan our full love, support and best wishes in his recovery and will assist where we can at every step of the way.”