 |
 |
 |
 |
 |
 |
Homepage > Cancer Information Centre > Cancer Facts > What Is Cancer?
Two in five people will be affected by cancer at some stage in their lives. Cancer is not one disease but many, all with some similar features but all with a distinctive character, which varies according to the cancer's type and location. The most common types of cancer are listed in the two tables below.
There are over 200 types of cancer, but all start in the same way. The control signals in a normal cell in the body go wrong, resulting in an abnormal cell. Cells normally divide in a controlled way, but abnormal cells keep on dividing, which can form a lump.
This cluster of abnormal cells is called a tumour. Some tumours are benign, or harmless, and often don't need treatment. But malignant tumours - the cancers - can spread. They may be dangerous because they can invade nearby parts of the body and stop them working properly. Cells from malignant tumours can break away and travel to other parts of the body, where they can form new groups of abnormal cells, called secondary growths.
What causes cancer in the first place, and how quickly the cells grow and spread, is different from person to person. A large number of people with cancer overcome the disease and live fulfilled lives for many years.
Ten most common cancers in women (diagnosed in the UK, 1998)
Breast
|
29%
|
Colorectal (large bowel)
|
13%
|
Lung
|
11%
|
Ovary
|
5%
|
Uterus
|
4%
|
Stomach
|
3%
|
Bladder
|
3%
|
Non-Hodgkin's lymphoma
|
3%
|
Pancreas
|
3%
|
Melanoma
|
3%
|
Ten most common cancers in men (diagnosed in the UK, 1998)
Lung
|
19%
|
Prostate
|
18%
|
Colorectal (large bowel)
|
14%
|
Bladder
|
7%
|
Stomach
|
5%
|
Head and neck
|
4%
|
Oesophagus
|
3%
|
Non-Hodgkin's lymphoma
|
3%
|
Leukaemia
|
3%
|
Kidney
|
3%
|
Source: Cancer Research UK 2002
Excludes non-melanoma skin cancer