Former U.S. President Jimmy Carter is now cancer-free, a friend and former church members told the Atlanta Journal-Constitution Sunday. Carter, 91, announced in August doctors found four small tumors on his brain. Family members have recently said the 39th president was recovering well after undergoing radiation treatment.

Carter was teaching a Sunday school class at Maranatha Baptist Church in his hometown of Plains, Georgia, when he made the surprise announcement, said Jill Stuckey, a close friend of the Carter family and a board member of the Friends of Jimmy Carter National Historic Site in Georgia.

“He said he got a scan this week, and the cancer was gone,” she told the Journal-Constitution, adding Carter was speaking to roughly 350 people at the time. “The church, everybody here, just erupted in applause.”

That's good news for Carter, who announced earlier this year melanoma spots had been found on his liver and brain. Carter immediately began radiation treatment and was administered a recently approved drug to boost his immune system. Carter also said he would step back from the human rights organization he founded after leaving the White House though “there has been no evidence of that at all,” Carter's grandson Jason told reporters last week.

“Their peace with where they are in their lives and where they've been in this world has really allowed them to take in this outpouring of support that has been just incredible,” Jason Carter told members of the Atlanta Press Club last week. “It takes an incredible human being to have a diagnosis like this be almost a happy time for them.”

Jimmy Carter appeared at a Habitat for Humanity building project in Memphis last month, saying he had finished his four scheduled rounds of treatment and felt better.

Carter was president from 1977 to 1981. After leaving the White House he became an active diplomat, philanthropist and author. Carter won a Nobel Peace Prize in 2002, for his ability to "find peaceful solutions to international conflicts, to advance democracy and human rights and to promote economic and social development" around the world.