Former Prime Minister Boris Johnson has claimed that Queen Elizabeth II suffered from a form of deadly bone cancer before her death.

As part of his upcoming tell-all memoir 'Unleashed', Mr Johnson recalled his final meeting with the monarch, stating he had been aware of her condition for over a year. 

'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,' he wrote.

'She seemed pale and more stooped, and she had dark ­bruising on her hands and wrists, probably from drips or injections.'

However, despite her condition, the former PM recalled how sharp her mind remained in that final meeting. 

The late Queen died at the age of 96 on September 8, 2022, at 3.10pm. The royal household has never confirmed a diagnosis suffered by the late monarch, and 'old age' was documented as cause of death, per her death certificate.

However, death in advanced years is typically due to another condition that is exacerbated by age, perhaps because treatment is less effective.

Bone cancer is considered a rare form of the disease accounting for less than 1 per cent of all cancer diagnosed each year, with only some 600 cases. 

The disease develops when cells in or near a bone develop DNA change that cause them to rapidly divide and multiply too rapidly. 

Some bone tumors cause a traditional tumour, although this might not happen until sometime after the area becomes painful. 

Age is considered the biggest risk factor for the disease with people in their late 80s most likely to be diagnosed. 

Bone cancer is incredibly deadly. Only about 50 per cent of patients are expected to live five years after their diagnosis. 

According to the NHS, bone cancer can develop in any bone in the body, but is most commonly found in the long bones of the arms and legs.

Symptoms of bone cancer include a persistent bone pain that gets worse over time and that continues into the night, swelling and redness over a bone, weak bones that fracture more easily, and problems moving.

Treatment, like most cancers, depends on what stage the cancer is spotted at as well as a patient's general health.

Surgery to remove the cancerous bone and replace it with an artificial substitute is sometimes possible although amputation can be necessary.

This can also be combined with cancer treatments like chemotherapy and radiotherapy to target the tumour directly. 

Mr Johnson's comments aren't the first to suggest Queen Elizabeth II suffered cancer towards the end of her life. 

Gyles Brandreth, a friend of Prince Philip who wrote the biography 'Elizabeth: An Intimate Portrait', previously told the Daily Mail the late monarch had a type of bone marrow cancer. 

He wrote: 'I had heard that the Queen had a form of myeloma — bone marrow cancer — which would explain her tiredness and weight loss and those "mobility issues" we were often told about during the last year or so of her life.'

'The most common symptom of myeloma is bone pain, especially in the pelvis and lower back, and multiple myeloma is a disease that often affects the elderly.

'Currently, there is no known cure, but treatment — including medicines to help regulate the immune system and drugs that help prevent the weakening of the bones — can reduce the severity of its symptoms and extend the patient's survival by months or two to three years.'

While 'old age' can be listed as contributing to a death, official guidelines state it should only be used as sole cause of death in very limited circumstances.

There is no official age limit for saying someone died of 'old age', but it is generally only accepted if the person is over 80.

The doctor should also have cared for the deceased for years or months and noticed a general decline in their health, as well as their functioning in day-to-day life.

There must also be no obvious identifiable disease or injury that contributed to their death, though 'old age' can be listed as contributing factor.

The final official condition for using 'old age' as the cause of death is that the doctor is 'certain' there is no reason that the death should be reported to the coroner for further investigation.

Medics are often warned against listing 'old age' as the cause of death in most circumstances.

This is because the family of deceased may not feel 'old age' is an adequate reason why their loved one has died.

Medics may also need to provide evidence of their reasoning to coroners or health and social care regulators if they have any reason to doubt the doctor's decision.

Attributing deaths solely 'old age' should also be avoided in hospitals as it is unlikely an elderly person is in hospital with no underlying disease or injury.

Anyone experiencing persistent, severe or worsening bone pain is encouraged to visit their GP.

While such issues are unlikely to be bone cancer it's important they are investigated.