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| [[Colorectal cancer medical therapy|Medical therapy]] | [[Colorectal cancer surgery|Surgical options]] | [[Colorectal cancer metastasis treatment|Metastasis Treatment]] | [[Colorectal cancer primary prevention|Primary prevention]] | [[Colorectal cancer secondary prevention|Secondary prevention]] | [[Colorectal cancer cost-effectiveness of therapy|Financial costs]] | [[Colorectal cancer future or investigational therapies|Future therapies]] | | [[Colorectal cancer medical therapy|Medical therapy]] | [[Colorectal cancer surgery|Surgical options]] | [[Colorectal cancer metastasis treatment|Metastasis Treatment]] | [[Colorectal cancer primary prevention|Primary prevention]] | [[Colorectal cancer secondary prevention|Secondary prevention]] | [[Colorectal cancer cost-effectiveness of therapy|Financial costs]] | [[Colorectal cancer future or investigational therapies|Future therapies]] |
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| ==Prevention==
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| Most colorectal cancers should be preventable, through increased surveillance, improved lifestyle, and, probably, the use of dietary chemopreventative agents.
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| ===Surveillance===
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| Most colorectal cancer arise from adenomatous polyps. These lesions can be detected and removed during [[colonoscopy]]. Studies show this procedure would decrease by > 80% the risk of cancer death, provided it is started by the age of 50, and repeated every 5 or 10 years.<ref>Winawer SJ, Zauber AG, Ho MN, O'Brien MJ, Gottlieb LS, Sternberg SS, Waye JD, Schapiro M, Bond JH, Panish JF, Ackroyd F, Shike M, Kurtz RC, Hornsby-Lewis L, Gerdes H, Stewart ET, The National Polyp Study Workgroup. ''Prevention of colorectal cancer by colonoscopic polypectomy.'' [[N Engl J Med]] 1993;329:1977-81. PMID 8247072.</ref>
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| As per current guidelines under [[National Comprehensive Cancer Network]], in average risk individuals with negative family history of colon cancer and personal history negative for [[adenomas]] or [[Inflammatory Bowel diseases]], flexible sigmoidoscopy every 5 years with fecal occult blood testing annually or double contrast barium enema are other options acceptable for screening rather than colonoscopy every 10 years (which is currently the Gold-Standard of care).
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| ===Lifestyle & Nutrition===
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| The comparison of colorectal cancer incidence in various countries strongly suggests that sedentarity, overeating (i.e., high caloric intake), and perhaps a diet high in meat (red or processed) could increase the risk of colorectal cancer. In contrast, a healthy body weight, physical fitness, and good nutrition decreases cancer risk in general. Accordingly, lifestyle changes could decrease the risk of colorectal cancer as much as 60-80%.<ref>{{cite journal|last=Cummings |first=JH |coauthors=Bingham SA |title=Diet and the prevention of cancer |journal=[[British Medical Journal|BMJ]] |year=1998|issue317|pages=1636-40 |url=http://bmj.bmjjournals.com/ |id=PMID 9848907}}</ref>
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| A high intake of dietary fiber (from eating fruits, vegetables, cereals, and other high fiber food products) has, until recently, been thought to reduce the risk of colorectal cancer and adenoma. In the largest study ever to examine this theory (88,757 subjects tracked over 16 years), it has been found that a fiber rich diet does not reduce the risk of colon cancer. <ref>{{cite journal |title=Dietary Fiber and the Risk of Colorectal Cancer and Adenoma in Women |journal=New England Journal of Medicine |year=1999 |issue=340 |pages=169-76 |url=http://content.nejm.org/cgi/content/full/340/3/169}}</ref> A 2005 meta-analysis study further supports these findings.<ref>{{cite journal |title=Dietary Fiber and Colorectal Cancer: An Ongoing Saga |journal=Journal of the American Medical Association |year=2005 |issue=294(22) |pages=2904 - 2906 |url=http://jama.ama-assn.org/cgi/content/extract/294/22/2904 |id=PMID 16352792}}</ref>
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| The Harvard School of Public Health states:
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| "Health Effects of Eating Fiber: Long heralded as part of a healthy diet, fiber appears to reduce the risk of developing various conditions, including heart disease, diabetes, diverticular disease, and constipation. Despite what many people may think, however, fiber probably has little, if any effect on colon cancer risk." <ref>{{cite web|title=Health Effects of Eating Fiber |url=http://www.hsph.harvard.edu/nutritionsource/fiber.html}}</ref>
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| ===Chemoprevention===
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| More than 200 agents, including the above cited phytochemicals, and other food components like calcium or folic acid (a B vitamin), and [[NSAID]]s like aspirin, are able to decrease carcinogenesis in preclinical models: Some studies show full inhibition of carcinogen-induced tumours in the colon of rats. Other studies show strong inhibition of spontaneous intestinal polyps in mutated mice (Min mice). Chemoprevention clinical trials in human volunteers have shown smaller prevention, but few intervention studies have been completed today. Calcium, aspirin and celecoxib supplements, given for 3 to 5 years after the removal of a polyp, decreased the recurrence of polyps in volunteers (by 15-40%). The "chemoprevention database" shows the results of all published scientific studies of chemopreventive agents, in people and in animals.<ref>{{cite web |url=http://www.inra.fr/reseau-nacre/sci-memb/corpet/indexan.html |title=Colorectal Cancer Prevention: Chemoprevention Database |accessdate=2007-08-23 |format= |work=}}</ref>
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| ====Aspirin chemoprophylaxis====
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| Aspirin should not be taken routinely to prevent colorectal cancer, even in people with a family history of the disease, because the risk of bleeding and kidney failure from high dose aspirin (300mg or more) outweigh the possible benefits.<ref>{{cite web |title=Task Force Recommends Against Use of Aspirin and Non-Steroidal Anti-Inflammatory Drugs to Prevent Colorectal Cancer |url=http://www.ahrq.gov/news/press/pr2007/aspnsaidpr.htm |author=Agency for Healthcare Research and Quality | accessdate=2007-05-07 |date=2007-03-05 |publisher=United States Department of Health & Human Services }}</ref>
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| A [[clinical practice guideline]] by the [http://www.ahrq.gov/clinic/uspstfix.htm U.S. Preventive Services Task Force (USPSTF)] recommended against taking [[aspirin]] ([http://www.ahrq.gov/clinic/3rduspstf/ratings.htm grade D recommendation]).<ref name="pmid17339621">{{cite journal |author= |title=Routine aspirin or nonsteroidal anti-inflammatory drugs for the primary prevention of colorectal cancer: U.S. Preventive Services Task Force recommendation statement |journal=Ann. Intern. Med. |volume=146 |issue=5 |pages=361-4 |year=2007 |id=pmid=17339621 |doi=}} PMID 17339621</ref> The Task Force acknowledged that aspirin may reduce the incidence of colorectal cancer, but "concluded that harms outweigh the benefits of aspirin and NSAID use for the prevention of colorectal cancer". A subsequent [[meta-analysis]] concluded "300 mg or more of aspirin a day for about 5 years is effective in primary prevention of colorectal cancer in randomised controlled trials, with a latency of about 10 years".<ref name="pmid17499602">{{cite journal |author=Flossmann E, Rothwell PM |title=Effect of aspirin on long-term risk of colorectal cancer: consistent evidence from randomised and observational studies |journal=Lancet |volume=369 |issue=9573 |pages=1603-13 |year=2007 |pmid=17499602 |doi=10.1016/S0140-6736(07)60747-8}} PMID 17499602</ref> However, long-term doses over 81 mg per day may increase bleeding events.<ref name="pmid17488967">{{cite journal |author=Campbell CL, Smyth S, Montalescot G, Steinhubl SR |title=Aspirin dose for the prevention of cardiovascular disease: a systematic review |journal=JAMA |volume=297 |issue=18 |pages=2018-24 |year=2007 |pmid=17488967 |doi=10.1001/jama.297.18.2018}} PMID 17488967</ref>
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| ====Calcium====
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| A [[meta-analysis]] by the [[Cochrane Collaboration]] of [[randomized controlled trials]] published through 2002 concluded "Although the evidence from two RCTs suggests that calcium supplementation might contribute to a moderate degree to the prevention of colorectal adenomatous polyps, this does not constitute sufficient evidence to recommend the general use of calcium supplements to prevent colorectal cancer.".<ref name="pmid16034903">{{cite journal |author=Weingarten MA, Zalmanovici A, Yaphe J |title=Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyps |journal=Cochrane database of systematic reviews (Online) |volume= |issue=3 |pages=CD003548 |year=2005 |pmid=16034903 |doi=10.1002/14651858.CD003548.pub3}}</ref> Subsequently, one [[randomized controlled trial]] by the [[Women's Health Initiative]] (WHI) reported negative results.<ref name="pmid16481636">{{cite journal |author=Wactawski-Wende J, Kotchen JM, Anderson GL, ''et al'' |title=Calcium plus vitamin D supplementation and the risk of colorectal cancer |journal=N. Engl. J. Med. |volume=354 |issue=7 |pages=684-96 |year=2006 |pmid=16481636 |doi=10.1056/NEJMoa055222}}</ref> A second [[randomized controlled trial]] reported reduction in all cancers, but had insufficient colorectal cancers for analysis.<ref name="pmid17556697">{{cite journal |author=Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, Heaney RP |title=Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial |journal=Am. J. Clin. Nutr. |volume=85 |issue=6 |pages=1586-91 |year=2007 |pmid=17556697 |doi=|url=http://www.ajcn.org/cgi/content/full/85/6/1586}}</ref>
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| ==Mathematical modeling== | | ==Mathematical modeling== |