Editing Cancer (section)

=== Chemicals ===
{{Further|Alcohol and cancer|Smoking and cancer}}
[[File:Cancer smoking lung cancer correlation from NIH.svg|thumb|upright=1.35|The incidence of lung cancer is highly correlated with smoking.]]
Exposure to particular substances have been linked to specific types of cancer. These substances are called ''[[carcinogen]]s''.

[[Tobacco smoking|Tobacco smoke]], for example, causes 90% of lung cancer.<ref name="pmid9594919">{{cite journal |vauthors=Biesalski HK, Bueno de Mesquita B, Chesson A, Chytil F, Grimble R, Hermus RJ, Köhrle J, Lotan R, Norpoth K, Pastorino U, Thurnham D |title=European Consensus Statement on Lung Cancer: risk factors and prevention. Lung Cancer Panel |journal=CA: A Cancer Journal for Clinicians |volume=48 |issue=3 |pages=167–76; discussion 164–66 |year=1998 |pmid=9594919 |doi=10.3322/canjclin.48.3.167|s2cid=20891885 |doi-access=free }}</ref> Tobacco use can cause cancer throughout the body including in the mouth and throat, [[larynx]], [[esophagus]], stomach, bladder, kidney, cervix, colon/rectum, liver and [[pancreas]].<ref name="pmid12270001">{{cite journal |vauthors=Kuper H, Boffetta P, Adami HO |s2cid=6132726 |title=Tobacco use and cancer causation: association by tumour type |journal=Journal of Internal Medicine |volume=252 |issue=3 |pages=206–24 |date=September 2002 |pmid=12270001 |doi=10.1046/j.1365-2796.2002.01022.x|doi-access=free }}</ref><ref>{{Cite web |date=27 August 2019 |title=Cancer and Tobacco Use |url=https://www.cdc.gov/vitalsigns/cancerandtobacco/index.html |access-date=25 October 2023 |website=Centers for Disease Control and Prevention |language=en-us}}</ref> Tobacco smoke contains over fifty known carcinogens, including [[nitrosamine]]s and [[polycyclic aromatic hydrocarbon]]s.<ref name=Kuper/>

Tobacco is responsible for about one in five cancer deaths worldwide<ref name="Kuper">{{cite journal |vauthors=Kuper H, Adami HO, Boffetta P |s2cid=9172672 |title=Tobacco use, cancer causation and public health impact |journal=Journal of Internal Medicine |volume=251 |issue=6 |pages=455–66 |date=June 2002 |pmid=12028500 |doi=10.1046/j.1365-2796.2002.00993.x|doi-access=free }}</ref> and about one in three in the developed world.<ref name="Sasco">{{cite journal |vauthors=Sasco AJ, Secretan MB, Straif K |title=Tobacco smoking and cancer: a brief review of recent epidemiological evidence |journal=Lung Cancer |volume=45 | issue = Suppl 2 |pages=S3–9 |date=August 2004 |pmid=15552776 |doi=10.1016/j.lungcan.2004.07.998}}</ref> 
Lung cancer death rates in the United States have mirrored [[tobacco smoking|smoking]] patterns, with increases in smoking followed by dramatic increases in lung cancer death rates and, more recently, decreases in smoking rates since the 1950s followed by decreases in lung cancer death rates in men since 1990.<ref name="pmid16998161">{{cite journal |vauthors=Thun MJ, Jemal A |title=How much of the decrease in cancer death rates in the United States is attributable to reductions in tobacco smoking? |journal=Tobacco Control |volume=15 |issue=5 |pages=345–47 |date=October 2006 |pmid=16998161 |pmc=2563648 |doi=10.1136/tc.2006.017749}}</ref><ref name="pmid18434333">{{cite journal |vauthors=Dubey S, Powell CA |title=Update in lung cancer 2007 |journal=American Journal of Respiratory and Critical Care Medicine |volume=177 |issue=9 |pages=941–46 |date=May 2008 |pmid=18434333 |pmc=2720127 |doi=10.1164/rccm.200801-107UP}}</ref>

Alcohol increases the risk of cancer of the breast (in women), throat, liver, oesophagus, mouth, larynx, and colon.<ref>{{cite news |title=US top doctor calls for cancer warnings on alcohol |url=https://www.bbc.com/news/articles/cj90x3np0zpo |agency=BBC}}</ref>
In Western Europe, 10% of cancers in males and 3% of cancers in females are attributed to alcohol exposure, especially liver and digestive tract cancers.<ref name="pmid21474525">{{cite journal |vauthors=Schütze M, Boeing H, Pischon T, Rehm J, Kehoe T, Gmel G, Olsen A, Tjønneland AM, Dahm CC, Overvad K, Clavel-Chapelon F, Boutron-Ruault MC, Trichopoulou A, Benetou V, Zylis D, Kaaks R, Rohrmann S, Palli D, Berrino F, Tumino R, Vineis P, Rodríguez L, Agudo A, Sánchez MJ, Dorronsoro M, Chirlaque MD, Barricarte A, Peeters PH, van Gils CH, Khaw KT, Wareham N, Allen NE, Key TJ, Boffetta P, Slimani N, Jenab M, Romaguera D, Wark PA, Riboli E, Bergmann MM |title=Alcohol attributable burden of incidence of cancer in eight European countries based on results from prospective cohort study |journal=BMJ |volume=342 |pages=d1584 |date=April 2011 |pmid=21474525 |pmc=3072472 |doi=10.1136/bmj.d1584}}</ref> Cancer from work-related substance exposures may cause between 2 and 20% of cases,<ref name="pmid18055160">{{cite journal |vauthors=Irigaray P, Newby JA, Clapp R, Hardell L, Howard V, Montagnier L, Epstein S, Belpomme D |title=Lifestyle-related factors and environmental agents causing cancer: an overview |journal=Biomedicine & Pharmacotherapy |volume=61 |issue=10 |pages=640–58 |date=December 2007 |pmid=18055160 |doi=10.1016/j.biopha.2007.10.006}}</ref> causing at least 200,000 deaths.<ref name="WHO_occup">{{cite press release |title=WHO calls for prevention of cancer through healthy workplaces |publisher=World Health Organization |date=27 April 2007 |url=https://www.who.int/mediacentre/news/notes/2007/np19/en/index.html |access-date=13 October 2007 |archive-url=https://web.archive.org/web/20071012202014/http://www.who.int/mediacentre/news/notes/2007/np19/en/index.html |archive-date=12 October 2007}}</ref> Cancers such as lung cancer and [[mesothelioma]] can come from inhaling tobacco smoke or [[asbestos]] fibers, or [[leukemia]] from exposure to [[benzene]].<ref name=WHO_occup/>

Exposure to [[perfluorooctanoic acid]] (PFOA), which is predominantly used in the production of [[Polytetrafluoroethylene|Teflon]], is known to cause two kinds of cancer.<ref>{{cite web |url= https://www.scientificamerican.com/article/erin-brockovich-blasts-u-s-regulation-of-toxic-chemicals/ |title= Erin Brockovich Blasts U.S. Regulation of Toxic Chemicals |website= scientificamerican.com | publisher= Scientific American |date= 28 December 2020}}</ref><ref>{{cite news |title=Environmental Pollutant, PFOA, Associated with Increased Risk of Kidney Cancer |url=https://dceg.cancer.gov/news-events/news/2020/pfoa-kidney |work=[[National Cancer Institute]] |date=24 September 2020}}</ref>

Chemotherapy drugs such as [[Platinum-based antineoplastic|platinum-based]] compounds are [[carcinogens]] that increase the risk of [[Secondary malignant neoplasm|secondary cancers]]<ref name=cds/>

[[Azathioprine]], an [[immunosuppressive medication]], is a [[carcinogen]] that can cause [[primary tumors]] to develop.<ref name=cds/>