More than two decades ago, King Charles III, who was Prince of Wales at the time, gave a speech in which he said he was told being diagnosed with a cancer was like "suddenly finding yourself in an unknown land".
The monarch, a patron of the Macmillan Cancer Support charity since 1997, has now found himself in that position after being diagnosed with the disease, which will ultimately affect one in two people during their lifetime.
Someone is diagnosed with cancer every two minutes in the UK.
At the age of 75, King Charles is in the most at-risk group.
The older a person is, the more likely they are to develop cancer: a third of all cases in the UK involve people aged 75 and over, Cancer Research UK says.
The risk increases because the cells in our bodies deteriorate over time and as damage builds, cancer can develop.
In his speech in 1999, to support a Macmillan campaign named A Voice for Life, he spoke of the need to "rewrite the rhetoric of cancer".
"People tell me that being diagnosed with a cancer is like suddenly finding yourself in an unknown land, with no map, no compass, no sign posts and no knowledge of the language," he said.
"The treatments are complex. Many different health professionals are involved – people can see as many as 50 different doctors. They need help to find their way in this no doubt alien and intimidating world."
Queen Elizabeth II, the king's mother, was reportedly suffering from multiple myeloma at the time of her death in 2022.
Her father, King George VI, who suffered from lung cancer, died 72 years ago to the day on February 6, 1952, due to a blood clot. That caused a coronary thrombosis, the blockage of arteries that carry blood to the heart, leading to a sudden collapse and fatal heart failure.
His death came as a shock to the public and the royal family – even the king had not been informed of the full extent of his illness.
His case is in stark contrast to that of the current monarch, who wanted to make his diagnosis public because of his long-running support for cancer charities.
A day before his illness was announced, the Royal Family shared a post on X to mark World Cancer Day, which said: "Today is #WorldCancerDay – a global initiative aiming to raise awareness about cancer. Earlier this week, Her Majesty The Queen opened @MaggiesCentres Royal Free, a new cancer support centre at Royal Free Hospital."
How King Charles was diagnosed
The king's condition was discovered while he was receiving treatment for a benign prostate enlargement last week, uncovering a “separate issue of concern”.
The nature of King Charles's cancer has not been disclosed, although Buckingham Palace said it was not of the prostate.
Men over 75 are prone to several types of cancer.
Britain's position in the league table
According to Cancer Research UK, the five-year relative survival for cancer in men is below the European average in England, Wales and Scotland.
A report last week commissioned by the group said progress in UK cancer survival is at its slowest in 50 years.
In a benchmarking exercise involving several provinces of Canada and parts of the UK, Ireland, Denmark, Norway, Sweden, Australia and New Zealand between 1995 and 2007, survival rates were higher in Australia, Canada and Sweden, intermediate in Norway and lower in Denmark and the UK.
Britain was ninth in terms of five-year survival rates from colon cancer; eighth for rectum cancer; seventh for lung, pancreatic and stomach, and sixth for ovarian.
Which types are most common?
In the UK, prostate cancer is the most common in men aged 75 and over, with lung cancer second, followed by bowel and bladder cancer.
Prostate, which the palace has confirmed is not affecting the king, accounts for a quarter of cancer diagnosed in men over 75.
About 16 per cent of cancers discovered in older men affect the lung. Smoking is the leading cause but the king does not smoke.
Bowel cancer accounts for 14 per cent of the disease found in men aged 75. Bleeding from the rectum and a change in bowel habits are among the most common symptoms.
Bladder cancer makes up about 6 per cent of cancer discovered in older men. Symptoms are similar to that of prostate cancer, with a frequent need to urinate, which may be painful. The urine can also contain blood.
King Charles III through the years – in pictures
Survival rates
Early-stage cancer (stage one) refers to a period when the disease has not begun to spread to other organs and treatment has more chance of success.
For example, more than nine in 10 people with bowel cancer survive the disease for five years or longer if diagnosed at stage one.
This falls to one in 10 if bowel cancer is diagnosed at the most advanced stage and has spread.
With bladder cancer, about 80 per cent of people survive for five years or more if diagnosed at an early stage.
This drops to 10 per cent at an advanced stage.
Age is another factor affecting survival rates. On average, 60 per cent of men survive five years or more after being diagnosed with bladder or bowel cancer in their seventies.
What is the king's prognosis?
The monarch’s cancer was caught early, according to UK Prime Minister Rishi Sunak, which should mean it is easier to treat.
Buckingham Palace said King Charles had now begun as “schedule of regular treatment” for the condition. His treatment could include chemotherapy, radiotherapy or medicine.
The palace said he was “wholly positive about his treatment” and “looks forward to returning to full public duty as soon as possible”.
