Former United States President Joe Biden’s prostate cancer has spread to his bones, according to his son, Hunter Biden.

Hunter disclosed the development in an interview with the BBC published on Saturday, saying the former president’s condition had become increasingly difficult for the family to witness.

He described the illness as painful and debilitating, adding that the cancer had metastasised beyond Biden’s bones.

“It’s very painful… very debilitating,” Hunter said, while expressing concern about the toll the disease has taken on his father.

He also spoke warmly about Biden’s role in the family, describing him as a devoted father, husband and grandfather who remains at the centre of the family.

Biden revealed in May 2025, several months after leaving office, that he had been diagnosed with an aggressive form of prostate cancer.

The former president had previously maintained an optimistic outlook about his treatment, saying doctors expected him to respond positively to medication.

He also thanked members of the public for their prayers and support, saying his treatment was progressing well.

Biden, 83, has spent more time with his family in recent months as he continues his treatment. His health was a major issue during the final period of his presidency and the 2024 election campaign.

He ended his bid for re-election in July 2024 and was replaced as the Democratic presidential candidate by then-Vice President Kamala Harris, who subsequently lost the election to Donald Trump.

Biden’s memoir, “Promise Me, America,” is expected to be released in November.