Are the number of cancer cases increasing or decreasing in the world?

Ask the expert
1 April 2008

Q: Are the number of cancer cases increasing or decreasing in the world?

A: Cancer is a leading cause of death worldwide and the total number of cases globally is increasing.

The number of global cancer deaths is projected to increase 45% from 2007 to 2030 (from 7.9 million to 11.5 million deaths), influenced in part by an increasing and aging global population. The estimated rise takes into account expected slight declines in death rates for some cancers in high resource countries. New cases of cancer in the same period are estimated to jump from 11.3 million in 2007 to 15.5 million in 2030.

In most developed countries, cancer is the second largest cause of death after cardiovascular disease, and epidemiological evidence points to this trend emerging in the less developed world. This is particularly true in countries in "transition" or middle-income countries, such as in South America and Asia. Already more than half of all cancer cases occur in developing countries.

Lung cancer kills more people than any other cancer - a trend that is expected to continue until 2030, unless efforts for global tobacco control are greatly intensified. Some cancers are more common in developed countries: prostate, breast and colon. Liver, stomach and cervical cancer are more common in developing countries.

A number of common risk factors have been linked to the development of cancer: an unhealthy lifestyle (including tobacco and alcohol use, inadequate diet, physical inactivity), and exposure to occupational (e.g. asbestos) or environmental carcinogens, (e.g. indoor air pollution), radiation (e.g. ultraviolet and ionizing radiation), and some infections (such as hepatitis B or human papilloma virus infection).

Key risk factors for cancer that can be avoided are:

  • tobacco use - responsible for 1.8 million cancer deaths per year (60% of these deaths occur in low- and middle-income countries);
  • being overweight, obese or physically inactive - together responsible for 274 000 cancer deaths per year;
  • harmful alcohol use - responsible for 351 000 cancer deaths per year;
  • sexually transmitted human papilloma virus (HPV) infection - responsible for 235 000 cancer deaths per year; and
  • occupational carcinogens - responsible for at least 152 000 cancer deaths per year.

Cancer prevention is an essential component of all cancer control plans because about 40% of all cancer deaths can be prevented.

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