Former US President Joe Biden’s prostate cancer has spread beyond his bones and is very painful, 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. A Biden spokesman said in October he was undergoing radiation treatment and hormone therapy. Biden was the oldest person to win the US presidency at the time of his election in 2020. Biden served as Obama’s vice president from 2009 to 2017.