Each year more than a quarter of a million people are diagnosed with cancer in the UK, and 1 in 3 people will develop cancer during their lifetime. But cancer is not common in children or young people - it mainly occurs in the later years of life. Cancers can occur at any age, but the risk of developing cancer increases with age. 64% (64 in 100) of all newly diagnosed cancers occur in people aged 65 years or more. Less than 1% (1 in 100) of cancers are diagnosed in children, aged 0-14 years.

Some cancers are very common and others are very rare. The most recent statistics for the UK (from 2003) show that for men the most common cancer is prostate cancer (23%), followed by lung cancer (16%), large bowel cancer (14%) and bladder cancer (5%).