Boris Johnson claims in new memoir that Queen Elizabeth II had bone cancer

The late Queen Elizabeth II suffered from bone cancer for more than a year before her death in 2022 at the age of 96, according to a claim made by former British Prime Minister Boris Johnson in his upcoming memoir.

Johnson, who met with the queen at Balmoral Castle just a few days before her death on Sept. 8, 2022, writes in his memoir, titled "Unleashed," about the queen's appearance in their final meeting.

"She seemed pale and more stooped, and she had dark bruising on her hands and wrists, probably from drips or injections," Johnson writes, adding, "She had known all summer that she was going, but was determined to hang on and do her last duty."

Of her alleged bone cancer diagnosis, Johnson writes, "I had known for a year or more that she had a form of bone cancer, and her doctors were worried that at any time she could enter a sharp decline."

Buckingham Palace has never said that the late queen had bone cancer. The palace also declined to comment to ABC News on Johnson's new book.

The cause of death on the queen's death certificate is listed as old age.

Johnson writes that though the queen appeared to have physical problems in their last meeting on Sept. 6, 2022, she was mentally sharp.

"But her mind ... was completely unimpaired ... she still flashed that great white smile in its sudden mood-lifting beauty," he writes.

The last public photo of Elizabeth shows her meeting with Liz Truss, then Britain's Prime Minister-elect, at Balmoral Castle following Johnson's resignation as prime minister. It was the first time in the queen's 70-year reign that the ceremonial transfer of power was held at Balmoral, rather than at Buckingham Palace in London.

During the queen's reign, the palace always fiercely guarded her medical privacy.

"What the former Prime Minister Boris Johnson has done here is share a private piece of information that he had from the late queen," Chris Ship, royal editor of ITV News, told ABC News. "She clearly did not want to share her health condition."

In contrast, Elizabeth's eldest son, King Charles III, has been public about his cancer diagnosis.

The palace announced on Feb. 5, that Charles had been diagnosed with cancer following treatment for benign prostate enlargement. It has not disclosed publicly what type of cancer Charles was diagnosed with, nor what type of treatment he is undergoing.

The king's daughter-in-law, Princess Kate, also announced her own cancer diagnosis this year, sharing publicly in March that she had been diagnosed with cancer.

She has not revealed publicly what type of cancer she faced, nor exact details of her treatment beyond that she underwent "preventative chemotherapy."

"There has been a generational shift [with] the current king sharing his cancer diagnosis, and Kate has told us that she's undergoing chemotherapy treatment," Ship said. "I's up to the individual how much they want to share with members of the public, and the late queen was someone who wanted to keep her medical condition as private as she possibly could."