Hart was born into a legendary wrestling family led by his father Stu Hart, the founder of Calgary’s Stampede Wrestling promotion.
Monday’s Instagram post had more than 8,000 likes within an hour of it going up.
“With hesitation and fear, I openly declare myself in my fight against prostate cancer,” Hart said.
Bret the Hitmen Hart with Stephanie Washington-Hart came out to help support the David Foster Foundation Miracle Gala and Concert in Calgary on September 27, 2014.
He made his debut in the WWF (now WWE) in 1984 and rose to fame as a member of the Hart Foundation with tag-team partner Jim (The Anvil) Neidhart.
Hart went on to win the WWF World Heavyweight Championship five times before an acrimonious split with the promotion.
He joined rival WCW, where he won the heavyweight title four times.
Hart has since mended fences with WWE and was inducted into the promotion’s Hall of Fame in 2006.