The King, who is currently undergoing treatment for his own undisclosed cancer, sent a personal message to Biden over the weekend, offering his best wishes after the diagnosis was made public, AFP reports.

King Charles III has written to former United States President, Joe Biden, following his diagnosis with an aggressive form of prostate cancer, the Buckingham Palace confirmed on Monday.

The King, who is currently undergoing treatment for his own undisclosed cancer, sent a personal message to Biden over the weekend, offering his best wishes after the diagnosis was made public, AFP reports.

Biden, 82, was diagnosed on Friday with a Gleason score of nine, indicating a highly aggressive form of the disease, according to a statement released by his office.

The statement added, “While this represents a more aggressive form of the disease, the cancer appears to be hormone-sensitive, which allows for effective management.”

It is understood that the cancer has already spread to his bones, but remains treatable due to its hormone sensitivity.

On Monday, Biden posted on social media for the first time since the announcement, expressing gratitude for the public’s support. 

“Cancer touches us all,” he wrote. “Like so many of you, Jill and I have learned that we are strongest in the broken places. Thank you for lifting us up with love and support.”

The two leaders have met on several occasions in recent years. Biden visited the UK for Queen Elizabeth II’s funeral in 2022 and previously held bilateral talks with Charles, then Prince of Wales, during the COP26 climate summit in Glasgow in 2021.

In July 2023, Biden joined the King for tea at Windsor Castle, with a palace spokesperson describing the meeting as “extremely cordial.” 

Biden had also expressed concern after King Charles’ own cancer diagnosis earlier in 2024. “I’m concerned about him. Just heard about his diagnosis. I’ll be talking to him, God willing,” he told reporters at the time.

He later posted on social media: “Navigating a cancer diagnosis, treatment, and survivorship takes hope and absolute courage.”

Last week, the King offered a rare comment about his condition, telling a former cancer patient during a visit to Bradford that he hoped to be on the “better side” of his treatment soon.

Prostate cancer remains the most common cancer among men in both the United States and the United Kingdom. 

The Gleason score, used to assess the disease’s severity, indicates higher aggressiveness when the score is higher.