ATLANTA – Former President Jimmy Carter said Wednesday that recent surgery to remove a small mass on his liver revealed he had cancer in other parts of his body.

The 90-year-old Georgia native said in a statement released by the Carter Center that he will be rearranging his schedule so he can undergo treatment by physicians at Emory Healthcare. His spokeswoman declined to elaborate, aside from saying an update would possibly be released next week.

The Carter Center said Aug. 3 that the former president had elective surgery to remove a small mass from his liver. His grandson, former state Sen. Jason Carter, thanked well-wishers on Twitter for their prayers.

Carter, a peanut farmer who became Georgia's governor, defeated Republican Gerald Ford in 1976 to become the nation's 39th president. He established a national energy policy and brokered a landmark peace deal between Israel and Egypt. But the end of his one term in the White House was marred by an energy crisis and an Iranian hostage standoff.

He lost the 1980 election to Republican Ronald Reagan. In the 35 years since, he has won the Nobel Peace Prize and logged millions of miles and visited dozens of countries on missions to monitor the globe to promote voting rights, settle conflicts, advocate for human rights and fight disease.

More recently, Carter played a mostly behind-the-scenes role in the campaign of Jason Carter, who waged a failed bid to unseat Republican Gov. Nathan Deal. The elder Carter provided his grandson with policy advice and fundraising heft. Near the end of the campaign, the former president headlined rallies and stumped door to door.

Residents of Plains, the southwest Georgia town where Carter lives and teaches Sunday school lessons, were struggling with the news.

"It's shocking us. It's just a shock to us," said Jennifer Jackson, who works at Plains Peanuts in the town's commercial strip. "He means so much to the town. And we want him to recover quickly and soon."

Jill Stuckey, a friend of the Carters, said residents have been "praying ever since we found out about the small mass on his liver."

Politicians sent messages offering him their prayers. Georgia Sens. Johnny Isakson and David Perdue, as well as former Florida Gov. Jeb Bush, were among them.

"We need his wisdom, his words and his leadership now more than ever before. We need him to continue to speak out on the great issues of our time," said Rep. John Lewis, D-Ga., in a statement. "I will keep him, his wife and his family in my prayers. He has my most hopeful wishes for a complete recovery."

President Obama offered this hope: "Jimmy, you're as resilient as they come, and along with the rest of America, we are rooting for you."

Carter recently finished a tour for his latest book, called "A Full Life: Reflections at 90." He acknowledged in a recent interview that he may be a rare president who left a bigger legacy outside the White House than when he held office.

"I had so much authority as president. I was able to bring peace to Israel for the first time in history. I was able to implement normal relations with China. I was able to keep our country at peace," he said.

"But at the Carter Center, the humanitarian aspect of my life has been far superior," he added. "Now we deal with individual families in the most remote and poverty stricken areas in the world."