October 2011

Key facts

  • Cancer is a leading cause of death worldwide: it accounted for 7.6 million deaths (around 13% of all deaths) in 2008.
  • 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 are due to the five leading behavioral and dietary risks: high body mass index, low fruit and vegetable intake, physical inactivity, tobacco use, alcohol use. All these cancers are often preventable.
  • Infectious agents are responsible for almost 22% of cancer deaths in the developing world and 6% in industrialized countries.
  • Tobacco use is the single largest preventable cause of cancer in the world causing 22% of cancer deaths. About 70% of the lung cancer burden can be attributed to smoking alone.
  • Cancer arises from a change in one single cell. The change may be started by external agents or inherited genetic factors.
  • About 70% of all cancer deaths in 2008 occurred in low- and middle-income countries.
  • Deaths from cancer worldwide are projected to continue to rise to over 11 million in 2030.

Modifying and avoiding risk factors

More than 30% of cancer could be prevented by modifying or avoiding key risk factors, including:

  • tobacco use
  • being overweight or obese
  • low fruit and vegetable intake
  • lack of physical activity
  • alcohol use
  • Human papillomavirus and Hepatitis B infection
  • urban air pollution
  • indoor smoke from household use of solid fuels.

Prevention strategies

  • Increase avoidance of the risk factors listed above.
  • Vaccinate against human papilloma virus (HPV) and hepatitis B virus (HBV).
  • Control occupational hazards.
  • Reduce exposure to sunlight.

Early detection

Cancer mortality can be reduced if cases are detected and treated early. There are two components of early detection efforts:

  • Early diagnosis
    • The awareness of early signs and symptoms (such as cervical, breast and oral cancers) in order to facilitate diagnosis and treatment before the disease becomes advanced.
    • Early diagnosis programmes are particularly relevant in low-resource settings where the majority of patients are diagnosed in very late stages.
  • Screening
    • The systematic application of a screening test in an asymptomatic population. It aims to identify individuals with abnormalities suggestive of a specific cancer or pre-cancer and refer them promptly for diagnosis and treatment.
    • Screening programmes are especially effective for frequent cancer types that have a screening test that is cost-effective, affordable, acceptable and accessible to the majority of the population at risk.