Former President Joe Biden addressed claims from the book Original Sin—by CNN’s Jake Tapper and Axios’s Alex Thompson—that he was mentally and physically diminished while in office.

At an event in Delaware, Biden responded defiantly, saying, “I can beat the hell out of both of them,” and dismissed doubts about his reelection bid by challenging critics: “Why didn’t they run against me then?” Biden said he has no regrets and remains proud of his presidential record, citing historians who rated him highly.

He also publicly confirmed, for the first time, his diagnosis of aggressive prostate cancer. Biden assured reporters that treatment has begun and that the outlook is optimistic. The cancer, found after worsening urinary symptoms, has metastasized but is hormone-sensitive, allowing for effective management. Critics, including Yale professor Dr. Howie Forman, questioned how such a late-stage diagnosis went undetected during his presidency, calling the situation “odd” and “inconceivable.”