Arizona Sen. John McCain has brain cancer and doctors have excised a fast-growing tumor discovered when he underwent surgery last week to remove a blood clot.
The Republican senator’s office and the Mayo Clinic Hospital in Phoenix made the announcement late Wednesday.
"The senator and his family are reviewing further treatment options with his Mayo team," the hospital said in a statement. "Treatment options may include a combination of chemotherapy and radiation."
McCain took to Twitter Thursday morning saying, "I greatly appreciate the outpouring of support -- unfortunately for my sparring partners in Congress, I'll be back soon, so stand-by!"
The news prompted an immediate outpouring of support from congressional colleagues.
Senate Majority Leader Mitch McConnell of Kentucky said McCain was a fighter. “He will face this challenge with the same extraordinary courage that has characterized his life,” the Republican said.
McCain’s eldest daughter, Meghan, said her dad was calmer than anyone else in his family after receiving the diagnosis.
“It won’t surprise you to learn that in all of this, the one of us who is the most confident and calm is my father,” she said. “He is the toughest person I know.”
President Trump also sent along his well wishes in a statement Wednesday night, saying, “Senator John McCain has always been a fighter. Melania and I send our thoughts and prayers to Senator McCain, Cindy, and their entire family. Get well soon.
Former President Barack Obama tweeted, "John McCain is an American hero."
John McCain is an American hero & one of the bravest fighters I've ever known. Cancer doesn't know what it's up against. Give it hell, John.— Barack Obama (@BarackObama) July 20, 2017
President Trump said McCain "Has always been a fighter. Melania and I send our thoughts and prayers." During Trump's election campaign, he criticized McCain for having been "captured" as a prisoner of war in Vietnam.
Former President Bill Clinton wrote on social media: "As she's shown his entire life, don't bet against John McCain. Best wishes to him for a swift recovery."
The 80-year-old has been representing Arizona since 1987 and was the GOP nominee for president in 2008. The tough-talking former Navy pilot was a prisoner during the Vietnam War.
He has previously battled skin cancer and underwent surgeries to remove malignant patches of skin.