Senator John McCain, 80, has been diagnosed with brain cancer.
At the request of McCain and his family, the Mayo Clinic released a statement about the Arizona senator on Wednesday.
“On Friday, July 14, Sen. John McCain underwent a procedure to remove a blood clot from above his left eye at Mayo Clinic Hospital in Pheonix,” the statement read.
“Subsequent tissue pathology revealed that a primary brain tumor known as a glioblastoma was associated with the blood clot.”
Officials at the clinic said he is reviewing treatment options, but that he is recovering from his surgery “amazingly well.” Treatment options may include a combination of chemotherapy and radiation.
McCain is a six-term Republican senator and former presidential nominee. He is also a three-time survivor of melanoma.
WATCH: Sen. John Hoeven calls John McCain a ‘real warrior’ after brain cancer diagnosis
Records of his medical exams released in 2008 when he was the GOP candidate for president showed that he has had precancerous skin lesions removed and an early stage squamous cell carcinoma, an easily cured skin cancer, removed.
In a statement released by his office, McCain said he appreciated the outpouring of support he’s received and that he’s in good spirits.
“He is grateful to the doctors and staff at Mayo Clinic for their outstanding care, and is confident that any future treatment will be effective,” the statement reads.
Last week, Senate Majority Leader Mitch McConnell delayed a vote on health care legislation due to McCain’s surgery, after the newest health care bill received heavy criticism. McCain’s absence meant it would become impossible to round up the votes needed to move forward with the bill. The bill still failed to get the necessary support needed to be passed into legislation.
According to the American Brain Tumor Association, glioblastomas can grow rapidly and are highly malignant.
WATCH: Sen. John Kennedy says everybody was ‘shocked and upset’ about Sen. John McCain’s cancer diagnosis
About 20,000 people in the U.S. each year are diagnosed with a glioblastoma, a particularly aggressive type of brain tumour. The American Cancer Society puts the five-year survival rate for patients over 55 at about 4 per cent.
The tumour digs tentacle-like roots into normal brain tissue. Patients fare best when surgeons can cut out all the visible tumour, which happened with McCain’s tumour, according to his office.
That isn’t a cure; cancerous cells that aren’t visible still tend to lurk, the reason McCain’s doctors are considering further treatment.
McCain’s daughter Meghan released a statement on Twitter saying she is now living “with the anxiety about what comes next.”
“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 wrote. “He is the toughest person I know. The cruelest enemy could not break him. The aggression of political life could not bend him.
“So he is meeting this challenge as he has every other. Cancer may afflict him in many ways: but it will not make him surrender. Nothing ever has.”
McConnell called McCain, the chairman of the Armed Services Committee, and a prisoner of war during the Vietnam War, a hero and said he looked forward to having him back in Washington.
“We all look forward to seeing this American hero again soon,” McConnell said in a statement.
In a statement, U.S. President Donald Trump said McCain has “always been a fighter.”
“Melania and I send out thoughts and prayers to Senator McCain, Cindy, and their entire family. Get well soon.”
Other colleagues also sent their well wishes on social media.
*With files from Reuters and the Associated Press
© 2017 Global News, a division of Corus Entertainment Inc.