Sen. John McCain tweeted Thursday morning that he was thankful for the "outpouring of support" he received after his brain cancer diagnosis and assured his Republican colleagues he will be back soon.
I greatly appreciate the outpouring of support - unfortunately for my sparring partners in Congress, I'll be back soon, so stand-by!— John McCain (@SenJohnMcCain) July 20, 2017
The tweet was McCain's first public comment since the revelation that he had been diagnosed with aggressive brain cancer.
His wife, Cindy McCain, tweeted hours earlier about her appreciation for the support her family has received.
Sen. John McCain (R-AZ) has been diagnosed with brain cancer following surgery he had last weekend, according to CNN.
BULLETIN - Senator John McCain has been diagnosed with brain cancer after pathology was performed following this weekend's surgery— Steve Brusk (@stevebruskCNN) July 20, 2017
McCain’s office on Wednesday released a statement saying that a Mayo Clinic in Phoenix discovered a brain tumor inside him last Friday.
“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 Phoenix,” the statement said.
“Subsequent tissue pathology revealed that a primary brain tumor known as glioblastoma was associated with the blood clot,” it added.
“The Senator and his family are reviewing further treatment options with his Mayo Clinic care team. Treatment options may include a combination of chemotherapy and radiation.”
Some Twitter users on Wednesday voiced support for McCain, who sought the presidency as a Republican in 2008.
McCain’s tumor was reportedly discovered while he was undergoing a procedure last week to remove a blood clot from above his left eye.
Fox News’s Meghan McCain, who is John McCain’s daughter, released a statement Wednesday saying her father’s illness “has effected everyone of us in the McCain family.”
“If we could ask anything of anyone now, it would be the prayers of those who understand this all well,” she said. “We would be grateful for them.”
“[My father] is the toughest person I know,” Meghan McCain added. “The cruelest enemy could not break 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.”
Former President Barack Obama, who defeated McCain for the presidency in 2008, called the senator "an American hero" on Twitter.
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
House Majority Whip Steve Scalise (R-LA), the No. 3 Republican in the lower chamber, echoed Obama's comments Wednesday.
Speaker Paul Ryan (R-WI) said in a statement Wednesday that McCain "has always been a warrior" in the face of adversity.
"It's who he is," he said. "I know John is going to fight this with the same sheer force of will that earned him the admiration of the nation."
"And all of us, not as Republicans or Democrats, but as Americans, are behind him. The prayers of the whole House are with Senator McCain and his family."
McCain was previously treated for a skin cancer called melanoma in 2000, and the former Navy captain’s new battle with illness comes as he is 80 years old.