Former US President Joe Biden’s prostate cancer has spread beyond his bones and is causing him significant pain, his son Hunter Biden said in an interview with the BBC.

“The cancer has spread, metastasised into his bones and further,” Hunter Biden told BBC’s Newsnight, according to video posted online on Friday. “It’s very painful, and it’s very debilitating in many respects.”

Hunter Biden became emotional while discussing his father’s condition.

“It’s really, really hard, and it’s really sad to watch,” he said, adding that his father remained active and committed to the United States.

A spokesman for the 83-year-old Biden declined to comment on the interview on Saturday.

Biden revealed in May 2025, less than four months after leaving the White House, that he had been diagnosed with an aggressive form of prostate cancer that had already spread to his bones.

He later underwent radiation and hormone therapy. Last month, while announcing his forthcoming memoir, Biden said his treatment was going “really well”.

Biden’s health had been closely scrutinised during his presidency, particularly after his poor performance in a June 2024 debate against Donald Trump. Biden withdrew from the presidential race following pressure from fellow Democrats, and Vice President Kamala Harris became the Democratic nominee. Trump went on to defeat Harris in the November election.

Biden, who served as president from 2021 to 2025, was the oldest person to win the US presidency when he was elected in 2020. He had previously served as Barack Obama’s vice president from 2009 to 2017.

Despite his illness, Biden has continued to make public appearances. He attended the dedication of Obama’s presidential library in Chicago in June.

His presidential memoir is scheduled for release on November 17.