BATAVIA, N.Y. >> Buffalo Bills Hall of Fame quarterback Jim Kelly says he has been diagnosed with cancer in his upper jaw bone and will have surgery on Friday.

Kelly is suffering from squamous cell carcinoma, but he has recently undergone tests to show that the cancer is isolated in his jaw and has not spread to other parts of his body.

“The past couple of weeks have been difficult for me,” Kelly said. “Because of the nature of social media, I thought it would be best to share with everyone what has been going on with my health.”

The announcement was made Monday morning, just before the start of the quarterback’s Kelly For Kids charitable foundation’s annual celebrity golf tournament.

“Doctors have told me that my prognosis for recovery is very good,” he said.

Kelly will have part of the upper jaw removed, and is unsure whether he will require chemotherapy, which will be determined after surgery. The operation will be performed in Buffalo.

“We caught it in time,” Kelly said. “When you hear the word ‘cancer,’ it automatically scares you. It not only scared me, but my family. But it’s like everything. It’s another river to cross, another stumbling block. I’ve been to the top many times. And I’ve been to the bottom. It’s just one of the roller coaster rides I’ve been on throughout my life.

“It’s just another challenge for me and I know I’ll beat it.”

Kelly spent 11 seasons with the Bills before retiring following the 1996 campaign. He still holds nearly every significant career franchise passing record — 35,467 yards, 237 touchdowns and 26 300-yard games.

“The first thought is you say a prayer that everything works out OK,” said Bill Polian, former general manager of the Bills. “Secondly, he didn’t earn a reputation as the toughest guy ever to play quarterback for no reason at all. So if anybody can overcome this, Jim can. He takes challenges head on.”

Kelly was inducted into the Pro Football Hall of Fame in 2002.

“I am extremely confident in my road to recovery,” Kelly said. “I plan to tackle this challenge head on, as we Kellys always do, with toughness perseverance and faith.”

Concerns about the 53-year-old’s health were first raised last week when his wife, Jill Kelly, posted a message published on imgur.com. Without going into detail, Jill Kelly noted that the family was going through a “more serious battle under our roof,” and asked followers to pray for her husband “for healing.”

Later, a youth sports foundation in Sioux Falls, S.D., announced that Kelly would not be able to attend the Hy-Vee/Sanford Legends banquet on June 13 for personal reasons.

Jill Kelly noted the cancellation with a post on her Twitter account on Friday in responding to a person disappointed the quarterback won’t be attending the banquet.

“He is disappointed as well,” Jill wrote. “But his health must come first! Please pray for him:)”