Key Facts

• Cancer is a leading cause of death worldwide: it accounted for 7.9 million deaths (around 13% of all deaths) in 2007.
• Lung, stomach, liver, colon and breast cancer cause the most cancer deaths each year.
• The most frequent types of cancer differ between men and women.
• About 30% of cancer deaths can be prevented.
• Tobacco use is the single most important risk factor for cancer.
• Cancer arises from a change in one single cell. The change may be started by external agents and inherited genetic factors.