Senator John McCain Dead at 81

Arizona Sen. John McCain died Saturday at the age of 81.

The lawmaker revealed last July that he had been diagnosed with brain cancer, and just this past Friday announced he would discontinue treatment for the disease.

McCain's family said in a statement that while he "surpassed expectations for survival" for the aggressive glioblastoma, "the progress of the disease and the inexorable advance of age render their verdict."

"With his usual strength of will, he has now chosen to discontinue medical treatment," read a statement from McCain's family. "Our family is immensely grateful for the support and kindness of all his caregivers over the last year, and for the continuing outpouring of concern and affection from John's many friends and associates, and the many thousands of people who are keeping him in their prayers. God bless and thank you all."

At the time, McCain's daughter, The View co-host Meghan McCain, wrote on Twitter that she and the rest of their family are grateful for "all the love and generosity" shown to them throughout McCain's illness.

"My family is deeply appreciative of all the love and generosity you have shown us during this past year. Thank you for all your continued support and prayers. We could not have made it this far without you - you've given us strength to carry on," Meghan McCain wrote at the time.

The Republican continued his Senate duties as best he could from his family home in northern Arizona, but was unable to cast Senate votes by proxy or in absentia.

Days after McCain underwent a craniotomy to remove a blood clot above his eye last summer, he was diagnosed with stage 4 glioblastoma.

"I greatly appreciate the outpouring of support - unfortunately for my sparring partners in Congress, I'll be back soon, so stand-by!" McCain tweeted a message of hope and humor following the announcement.

McCain was receiving treatment at Walter Reed Medical Center in Bethesda, Maryland. In December, the politician was hospitalized following complications related to his cancer treatments. His condition, his office said, stemmed from "normal side effects" of his ongoing therapy, which included one round of chemo.

Meghan McCain began an emotional discussion about her father on The View in December, and received some comforting words from former Vice President Joe Biden, whose son Beau died of glioblastoma in 2015.

"There is hope, and if anybody can make it, your dad… her dad is one of my best friends," Biden told McCain and viewers. "The thing that I found, and Beau insisted on, and your dad's going to insist on, is you've got to maintain hope. You have to have hope."

McCain was first elected to the United States Senate in 1986. He then went on to run a pair of presidential campaigns in 2000 and 2008. In his last campaign, he partnered with Alaska Governor Sarah Palin. Though he lost both presidential elections, he continued to work in politics as an Arizona Senator from 1987 until his death.

McCain also actively worked on a memoir, to be shared in 2018.

"I've been a small bit of American history, so I think if there's something on my tombstone, it'll be 'He served his country,' and hopefully you add one word, 'honorably,' " McCain told PEOPLE.

"I've made a lot of mistakes. I've lost races. I've caved into what seems to be the easy way out and wasn't. There's nothing to be sorry for. I have nothing but gratitude for a life fully lived, and you can't ask for anything more than that. And you can't deny that I am the luckiest person that you will ever talk to," he said.