Cancer
A group of diseases involving uncontrolled cell growth and potential spread.
Last updated
The WHO reported nearly 10 million cancer deaths in 2024, making it a leading cause of death worldwide.[1] A defining characteristic of cancer is the rapid creation of abnormal cells that grow beyond usual boundaries and can invade adjoining body parts or spread to other organs, a process called metastasis.[1] The human body can be affected by more than one hundred distinct types of cancer.[2]
Key facts and history
The word "cancer" comes from the ancient Greek καρκίνος, meaning 'crab' and 'tumor'.[3] Tobacco use, alcohol, obesity, poor diet, and lack of exercise cause about 33% of cancer deaths.[4] Cancer risk increases significantly with age, and rates are rising as more people live to old age.[5][1] Around the year 1600, the term "cancer" entered the English language with its current medical meaning.[3]
Globally, between 16% and 18% of all cancers are linked to infections from specific viruses, bacteria, or parasites.[4] Inherited genetic defects are responsible for an estimated 5% to 10% of all cancer cases.[6] By 2019, the global number of new cancer cases each year had risen to 23.6 million, and the disease caused 10 million deaths annually.[7] Lung, prostate, colorectal, and stomach cancers are the types most frequently diagnosed in men.[5]
Breast, colorectal, lung, and cervical cancers are the types most frequently diagnosed in women.[5]
What the cited sources add
The WHO states that nearly a quarter of cancer deaths are due to tobacco, alcohol, high body mass index, low fruit and vegetable intake, and lack of physical activity.[1] The WHO notes that air pollution is an important risk factor for lung cancer.[1] Cancer-causing infections are responsible for approximately 30% of cancer cases in low- and lower-middle-income countries, according to the WHO.[1] The WHO states that approximately 38% of cancers can currently be prevented by avoiding risk factors and implementing evidence-based prevention strategies.[1]
The National Cancer Institute explains that metastatic cancer cells have features like the primary cancer, not like cells where the metastasis is found.[8] The National Cancer Institute lists the most common sites of metastasis as bone, liver, and lung.[8]
References
- "Cancer", www.who.int, 3 February 2025. facts only, no text reused. who.int
- Wikipedia, "Cancer" (CC BY-SA 4.0), which cites: "Cancer", www.who.int, 3 February 2025; "A to Z List of Cancer Types - NCI", www.cancer.gov, January 1980 (we also read that source) en.wikipedia.org
- Wikipedia, "Cancer" (CC BY-SA 4.0), which cites: "cancer", www.etymonline.com (original not read by us) en.wikipedia.org
- Wikipedia, "Cancer" (CC BY-SA 4.0), which cites: "Cancer", www.who.int, 3 February 2025; "Obesity and Cancer Risk", National Cancer Institute, 3 January 2012; "Long-Term Alcohol Consumption and Breast, Upper Aero-Digestive Tract and Colorectal Cancer Risk: A Systematic Review and Meta-Analysis", Alcohol and Alcoholism, May 2016, p. 315–30; "Cancer is a preventable disease that requires major lifestyle changes", Pharmaceutical Research, September 2008, p. 2097–116; "Global burden of cancer attributable to infections in 2018: a worldwide incidence analysis", The Lancet. Global Health, February 2 en.wikipedia.org
- Wikipedia, "Cancer" (CC BY-SA 4.0), which cites: "World Cancer Report 2014", World Health Organization, 2014, p. Chapter 1.1; "Cancer statistics, 2023", CA, January 2023, p. 17–48; "World Cancer Report 2014", World Health Organization, 2014, p. Chapter 4.7; "Cancer statistics, 2023", CA, January 2023, p. 17–48; "Nonmelanoma skin cancer", Facial Plastic Surgery Clinics of North America, February 2013, p. 43–53; "Epidemiology and economic burden of nonmelanoma skin cancer", Facial Plastic Surgery Clinics of North America, November 2012, p. 419–422; "World Cancer Report 2014", World Health Organi en.wikipedia.org
- Wikipedia, "Cancer" (CC BY-SA 4.0), which cites: "World Cancer Report 2014", World Health Organization, 2014, p. Chapter 4.7; "World Cancer Report 2014", World Health Organization, 2014, p. Chapter 4.7; "Heredity and Cancer", American Cancer Society; "Cancer", www.who.int, 3 February 2025; "How is cancer diagnosed?", American Cancer Society, 29 January 2013 (we also read that source) en.wikipedia.org
- Wikipedia, "Cancer" (CC BY-SA 4.0), which cites: GBD, "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990–2015: a systematic analysis for the Global Burden of Disease Study 2015", The Lancet, 8 Octo; "Cancer Incidence, Mortality, Years of Life Lost, Years Lived With Disability, and Disability-Adjusted Life Years for 29 Cancer Groups From 2010 to 2019: A Systematic Analysis for the Global Burden of Disease Study 2019"; "Metabolic Drivers in Hereditary Cancer Syndromes", Annual Review of Cancer Biology, 2020, p. 77–97 (origin en.wikipedia.org
- "Metastatic Cancer: Questions and Answers", National Cancer Institute, 12 May 2015. facts only, no text reused. cancer.gov
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Cancer (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.
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Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Cancer (CC BY-SA 4.0).
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