McCain in new book: 'Maybe I’ll be gone before you hear this'
© Greg Nash

Sen. John McCainJohn Sidney McCainPence met with silence after mentioning Trump in Munich speech Mark Kelly's campaign raises over M in days after launching Senate bid The Hill's 12:30 Report — Presented by Kidney Care Partners — Lawmakers wait for Trump's next move on border deal MORE (R-Ariz.) says in a recently released excerpt from his upcoming memoir that he isn't sure how much time he has left to live.

McCain, 81, was diagnosed with glioblastoma, an aggressive form of brain cancer, last year.

“I don’t know how much longer I’ll be here,” McCain says in his book “The Restless Wave: Good Times, Just Causes, Great Fights, and other Appreciations.” The excerpt was provided to NPR on Thursday.

Advances in oncology could uncover new cancer treatments that may extend his life, McCain says, noting that he could live another five years.

“Maybe I’ll be gone before you hear this,” he says. “My predicament is, well, rather unpredictable. But I’m prepared for either contingency or at least I’m getting prepared.”

Part of that plan, he says, includes talking to "my fellow Americans a little more."

McCain acknowledges in his book that this will be his last term in the Senate, according to other excerpts released last week.

“I’m freer than colleagues who will face the voters again. I can speak my mind without fearing the consequences much. And I can vote my conscience without worry,” he writes.

But the memoir isn't entirely apolitical — the senator also takes aim at President TrumpDonald John TrumpGillibrand backs federal classification of third gender: report Former Carter pollster, Bannon ally Patrick Caddell dies at 68 Heather Nauert withdraws her name from consideration for UN Ambassador job MORE. In it, McCain writes that the president seems to care more about “the appearance of toughness” than American values, chiding Trump's coziness with Russian President Vladimir Putin, in particular.

“The Restless Wave: Good Times, Just Causes, Great Fights, and other Appreciations.” will be released on May 22.