The senior senator from Arizona and two-time presidential candidate announced the diagnosis Wednesday. The news prompted an outpouring of support.

Ross D. Franklin / AP

John McCain, one of the highest-profile members of the US Senate and a two-time presidential candidate, announced Wednesday that he has been diagnosed with brain cancer.

The diagnosis came after McCain, 80, had a blood clot removed from above his left eye on July 14. "Subsequent tissue pathology revealed that a primary brain tumor known as a glioblastoma was associated with the blood clot," said a statement from the Mayo Clinic and released by his office. McCain and his family are reviewing further treatment options, which potentially include chemotherapy and radiation, and he is recovering "amazingly well," the statement said. McCain showed no neurological problems before or after the operation, his doctors told CNN. Before the surgery, McCain told his doctors he had, at times, felt foggy and not as sharp as normal, and was having double vision, according to CNN. However, after the surgery, the senator reportedly was oriented, had good balance, and experienced no headaches. He has been recovering at home since Saturday, when he was discharged from the hospital. Meghan McCain, the senator's daughter, said in a statement that the family was shocked by the diagnosis.

"It won't surprise you to learn that in all this, the one of us who is most confident and calm is my father," she said. "He is the toughest person I know. The cruelest enemy could not break him."

Horst Faas / AP John McCain is seen after his release from captivity in Vietnam in March 1973.

The blood clot was removed from near the spot where McCain was diagnosed with the aggressive skin cancer melanoma in 2000, notes CNN. The senator has also had three precancerous skin lesions removed, none of which were invasive, according to medical records released in 2008 during his presidential campaign. McCain began his political career as a Senate liaison while serving in the US Navy. In 1982, he won a seat in the US House of Representatives and in 1987 was elected to the the Senate, succeeding Barry Goldwater, another high-profile conservative.

McCain first ran for president in 1999, challenging George W. Bush for the Republican nomination. He lost, but went on to secure his party's nomination eight years later and ran against Barack Obama in the general election. McCain famously branded himself as a "maverick" during that election and selected Sarah Palin as his running mate, but ultimately lost to Obama. Prior to entering politics, McCain was a Navy pilot. In 1967, while flying a mission during the Vietnam War he was shot down and spent more than five years as a prisoner of war. McCain was tortured during his time in captivity and at one point refused release unless all the other prisoners captured before him were freed as well. News of McCain's cancer diagnosis prompted an outpouring of support. President Trump said in a statement that McCain "has always been a fighter." "Melania and I send our thoughts and prayers to Senator McCain, Cindy, and their entire family," Trump said. "Get well soon."

Obama, McCain's former rival, called him "an American hero and one of the bravest fighters I've ever known."

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.

Hillary Clinton similarly praised McCain, saying he "is as tough as they come." And Bill Clinton said "as he’s shown his entire life, don’t bet against John McCain." Former President George H.W. Bush released a statement saying, "The Hanoi Hilton couldn’t break John McCain’s spirit many years ago, so Barbara and I know — with confidence — he and his family will meet this latest battle in his singular life of service with courage and determination." His son, former President George W. Bush, also praised McCain and wished him a speedy recovery. "I was impressed by his spirit and determination," Bush said, after speaking with McCain by phone. Jeff Flake, McCain's fellow senator from Arizona, tweeted that it was a "tough diagnosis, but even tougher man."



Just spoke to @SenJohnMcCain. Tough diagnosis, but even tougher man.

In a series of tweets, Arizona Gov. Doug Ducey called McCain "undoubtedly the toughest man in the US Senate."

"He is an American hero and has served our country like few ever will," Ducey said. Former vice president Joe Biden said he has been friends with McCain for 40 years. "He's gotten through so much difficulty with so much grace," Biden said. "He is strong — and he will beat this." Senate Majority Leader Mitch McConnell said that McCain is "a hero to our conference and a hero to our country." "He has never shied away from a fight and I know that he will face this challenge with the same extraordinary courage that has characterized his life," McConnell said, adding: "We all look forward to seeing this American hero again soon." House Speaker Paul Ryan referred to McCain as a "warrior" in a statement, adding that "I know John is going to fight this with the same sheer force of will that has earned him the admiration of the nation."

According to reporters covering a Senate healthcare meeting Wednesday, lawmakers paused after learning of McCain's diagnosis and prayed. Numerous other lawmakers also wished McCain well. Among them, Kentucky Sen. Rand Paul promised to pray for him and his family. Utah Sen. Orrin Hatch said "few have served our nation more admirably than John McCain." And Nebraska Sen. Ben Sasse called McCain "an American hero and a relentless fighter." Vice President Mike Pence also tweeted that he was praying for McCain. "Cancer picked on the wrong guy," Pence said. "John McCain is a fighter and he'll win this fight too."

Responding to the outpouring of support on Twitter on Thursday, McCain said he'd be back in Congress soon:

I greatly appreciate the outpouring of support - unfortunately for my sparring partners in Congress, I'll be back soon, so stand-by!