Schilling ranks sixth all-time in wins (101) for Phillies pitchers, fourth in strikeouts (1,554), and eighth in innings pitched (1,6591/3). He was MVP of the National League Championship Series in 1993 but departed the franchise on bitter terms in 2000.
Schilling found glory in Arizona and Boston, winning three World Series as one of the best postseason pitchers of his generation. His 3,116 strikeouts over 20 seasons rank 15th in baseball history.
He finished 12th in Hall of Fame voting last month with 29.2 percent of the vote in his second year on the ballot. (At least 75 percent is needed for induction.) The Phillies honored Schilling last summer by placing him on the team's wall of fame.
Schilling has endured health issues before. He told the Boston Globe he suffered a heart attack in 2011 and needed surgery to insert a stent into one artery. He also used smokeless tobacco for years and in 1998 received a diagnosis of mild dysplasia, a condition that revealed abnormal cell changes in his mouth.
The former Phillies ace was told at the time that the condition was 100 percent reversible if he stopped using smokeless tobacco, but he eventually relapsed. Smokeless tobacco is highly addictive and is still used by many players in the big leagues.
"My whole lower lip is in bad shape," Schilling said in 1998. "The tissue is in a really bad state."
Schilling also acknowledged at that time how difficult it was to kick the habit. "I chose to dip," he said. "I didn't choose the addiction I'm stuck with. Breaking it is the hardest thing I've ever had to do in my life."
Schilling's wife, Shonda, overcame Stage 2 malignant melanoma in 2001.
"My father left me with a saying that I've carried my entire life and tried to pass on to our kids: 'Tough times don't last, tough people do,' " Schilling said in his statement. "Over the years in Boston, the kids at the Dana-Farber Cancer Institute have shown us what that means. With my incredibly talented medical team, I'm ready to try and win another big game. I've been so very blessed and I feel grateful for what God has allowed my family to have and experience, and I'll embrace this fight just like the rest of them, with resolute faith and head-on."
Schilling is the second star from the 1993 Phillies to reveal a cancer diagnosis within the last year. Former catcher Darren Daulton received a diagnosis of advanced brain cancer in July.