Editing Crohn's disease (section)

====Cancer====
Crohn's disease also increases the risk of [[cancer]] in the area of inflammation. For example, individuals with Crohn's disease involving the [[small bowel]] are at higher risk for [[small intestinal cancer]].<ref>{{cite journal | vauthors = Bye WA, Nguyen TM, Parker CE, Jairath V, East JE | title = Strategies for detecting colon cancer in patients with inflammatory bowel disease | journal = The Cochrane Database of Systematic Reviews | volume = 2017 | issue = 9 | pages = CD000279 | date = September 2017 | pmid = 28922695 | pmc = 6483622 | doi = 10.1002/14651858.CD000279.pub4 }}</ref> Similarly, people with [[Crohn's colitis]] have a [[relative risk]] of 5.6 for developing [[colon cancer]].<ref>{{cite journal | vauthors = Ekbom A, Helmick C, Zack M, Adami HO | title = Increased risk of large-bowel cancer in Crohn's disease with colonic involvement | journal = Lancet | volume = 336 | issue = 8711 | pages = 357–359 | date = August 1990 | pmid = 1975343 | doi = 10.1016/0140-6736(90)91889-I | url = https://zenodo.org/record/1258309 | access-date = September 4, 2018 | url-status = live | s2cid = 2046255 | archive-url = https://web.archive.org/web/20200805072047/https://zenodo.org/record/1258309 | archive-date = August 5, 2020 }}</ref> Screening for colon cancer with [[colonoscopy]] is recommended for anyone who has had Crohn's colitis for at least eight years.<ref>{{cite journal | vauthors = Itzkowitz SH, Present DH | title = Consensus conference: Colorectal cancer screening and surveillance in inflammatory bowel disease | journal = Inflammatory Bowel Diseases | volume = 11 | issue = 3 | pages = 314–321 | date = March 2005 | pmid = 15735438 | doi = 10.1097/01.mib.0000160811.76729.d5 | collaboration = Crohn's and Colitis Foundation of America Colon Cancer in IBD Study Group }}</ref>

Some studies suggest there is a role for chemoprotection in the prevention of colorectal cancer in Crohn's involving the colon; two agents have been suggested, [[folate]] and [[mesalamine]] preparations.<ref>{{cite journal | vauthors = Zisman TL, Rubin DT | title = Colorectal cancer and dysplasia in inflammatory bowel disease | journal = World Journal of Gastroenterology | volume = 14 | issue = 17 | pages = 2662–2669 | date = May 2008 | pmid = 18461651 | pmc = 2709054 | doi = 10.3748/wjg.14.2662 | doi-access = free | title-link = doi }}</ref> Also, [[immunotherapy|immunomodulators]] and [[biological therapy for inflammatory bowel disease|biologic agents]] used to treat this disease may promote the development of extra-intestinal cancers.<ref>{{cite journal | vauthors = Axelrad JE, Lichtiger S, Yajnik V | title = Inflammatory bowel disease and cancer: The role of inflammation, immunosuppression, and cancer treatment | journal = World Journal of Gastroenterology | volume = 22 | issue = 20 | pages = 4794–4801 | date = May 2016 | pmid = 27239106 | pmc = 4873872 | doi = 10.3748/wjg.v22.i20.4794 | type = Review | doi-access = free | title-link = doi }}</ref>

Some cancers, such as [[Acute myeloid leukemia|acute myelocytic leukaemia]] have been described in cases of Crohn's disease.<ref name="Manifestations" /> [[Hepatosplenic T-cell lymphoma]] (HSTCL) is a rare, lethal disease generally seen in young males with inflammatory bowel disease. TNF-α Inhibitor treatments ([[infliximab]], [[adalimumab]], [[Certolizumab pegol|certolizumab]], [[natalizumab]], and [[etanercept]]) are thought to be the cause of this rare disease.<ref>{{cite journal | vauthors = Parakkal D, Sifuentes H, Semer R, Ehrenpreis ED | title = Hepatosplenic T-cell lymphoma in patients receiving TNF-α inhibitor therapy: expanding the groups at risk | journal = European Journal of Gastroenterology & Hepatology | volume = 23 | issue = 12 | pages = 1150–1156 | date = November 2011 | pmid = 21941193 | doi = 10.1097/MEG.0b013e32834bb90a | s2cid = 27267004 }}</ref>

[[File:Colorectal cancer endo 2.jpg|thumb|[[Colonoscopy|Endoscopic]] image of colon cancer identified in the sigmoid colon on screening [[colonoscopy]] for Crohn's disease]]