The Minnesota Republican said in a social media post that the cancer that began in his neck and throat and is at its most advanced stage, according to the Minneapolis Star Tribune.
Coleman acknowledged that metastasized cancer doesn’t have a great prognosis, but his DNA was responsive to chemotherapy and radiation.
“My physicians at the Mayo Clinic remain optimistic that the beast can still be contained,” he said.
In the announcement, Coleman said a test of lung tissue showed lesions had spread to his lungs.
Coleman had his first surgery for cancer in 2015 after finding a squamous cancer cell in his right tonsil.
“Once it is in your body, even if you have wiped away all current traces of it, you live in fear that it will soon emerge from the microscopic shadows,” he said.
Coleman served one term in the Senate and won his term after his opponent Sen. Paul Wellstone died in a plane crash shortly before the race in 2002.
Coleman would lose his race for re-election to former Sen. Al Franken in 2008.
Initially a member of the Democratic Farmer-Labor party, Coleman switched parties while he was mayor of St. Paul.
Former Rep. John Kline told the Star Tribune he spoke with Coleman on Tuesday.
“He’s extraordinarily upbeat, laughing,” Kline said.
Coleman is currently a lobbyist for Hogan Lovells.
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