Spotting cancer early can boost survival rates
Spotting cancer early can increase survival rates and make treatments more effective.
Prime Minister Rishi Sunak, who holds weekly audiences with the King, said he was "shocked and sad" to hear about Charles' cancer diagnosis but "thankfully this has been caught early".
The chance of a person surviving for at least five years after an early diagnosis depends on the type of cancer.
Early stage cancer (stage 1) means the disease has not begun to spread to other organs and treatment is more likely to be successful.
For example, more than nine in 10 people with bowel cancer survive their disease for five years or more if diagnosed at the earliest stage 1.
This falls to one in 10 people if bowel cancer is diagnosed at the most advanced stage and has spread to other parts of the body.
With bladder cancer, around 80 per cent of people survive their cancer for five years or more if diagnosed at an early stage.
This drops to around 10 per cent of people when the bladder cancer is at an advanced stage.
However, for one of the most deadly cancers, pancreatic cancer, only around half of patients with stage 1 disease live for one year or more, dropping to around 10 percent for those with advanced cancer.
Each cancer is different, with things such as genetic changes meaning some cancers are more aggressive.
The particular subset of cancer can also have an effect.
For example, about 90 out of 100 bladder cancers in the UK are urothelial cancer, while 5 per cent are squamous cell cancer, which is usually invasive.
According to Cancer Research UK, people should always contact their doctor if something in their body does not look or feel quite right, or if they suspect they have cancer.