Normally the growth of all cells is carefully controlled in the
body. As cells die, they are replaced in an orderly fashion. Cancer
can develop when cells start to grow in an uncontrolled way. If
this happens in the prostate gland, prostate cancer can
develop.
Prostate cancer can grow slowly or very quickly. Most prostate
cancer is slow-growing to start with and may never cause any
problems or symptoms in a man's lifetime.
However, some men will have cancer that is more aggressive or 'high
risk.' This needs treatment to help prevent or delay it
spreading outside the prostate gland.