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| | __NOTOC__ |
| | {{Anal cancer}} |
| '''For patient information click [[{{PAGENAME}} (patient information)|here]]''' | | '''For patient information click [[{{PAGENAME}} (patient information)|here]]''' |
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| {{Editor Help}} | | {{CMG}} {{AE}} {{MJK}} |
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| ==Overview==
| | {{SK}}: Carcinoma of the anus; Anal carcinoma; |
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| '''Anal cancer''' is a type of [[cancer]] which arises from the [[anus]], the distal orifice of the [[gastrointestinal tract]]. It is a distinct entity from the more common [[colorectal cancer]]. The [[etiology]], risk factors, clinical progression, staging, and treatment are all different. Anal cancer is typically a [[squamous cell carcinoma]] that arises near the squamocolumnar junction.
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| ==Epidemiology== | | ==[[Anal cancer overview|Overview]]== |
| '''Incidence'''<ref>Anal Carcinoma [http://www.thedoctorsdoctor.com/diseases/anal_ca.htm#epidemiology]</ref>
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| *In women and men who do not engage in anal intercourse with other men - 0.9/100,000
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| *In HIV negative men who engage in anal intercourse with other men - 35/100,000
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| *In HIV positive men who engage in anal intercourse with other men - (estimated) 60-70/100,000
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| Anal cancer is uncommon and accounts for only 4% of all cancers of the lower alimentary tract. There are estimated to be 4,650 new cases and 690 deaths from anal cancer in the United States in 2007.<ref>National Cancer Institute: Anal Cancer [http://www.nci.nih.gov/cancertopics/pdq/treatment/anal/healthprofessional]</ref> | | ==[[Anal cancer historical perspective|Historical Perspective]]== |
| Because it is rare and because it occurs in a body part that is rarely discussed, most people are unaware of its existence.
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| ==Risk factors== | | ==[[Anal cancer classification|Classification]]== |
| *[[Human papillomavirus]] (HPV) infection: An examination of squamous cell carcinoma tumor tissues from patients in Denmark and Sweden showed a high proportion of anal cancers to be positive for the types of HPV that are also associated with high risk of cervical cancer (90% of the tumors from women, 100% of the tumors from homosexual men, and 58% of tumors from heterosexual men).<ref>Danish Medical Bulletin. 2002 Aug;49(3):194-209</ref> In another study done, high-risk types of HPV, notably HPV-16, were detected in 84 percent of anal cancer specimens examined.<ref>New England Journal of Medicine. 1997 Nov 6;337(19):1350-8</ref>
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| *Sexual activity: Having multiple sex partners or having [[anal sex]], due to the increased risk of exposure to the HPV virus.<ref name="ACS">American Cancer Society. [http://www.cancer.org/docroot/CRI/content/CRI_2_4_2X_What_are_the_risk_factors_for_Anal_Cancer_47.asp?sitearea "What Are the Risk Factors for Anal Cancer?"]</ref>
| | ==[[Anal cancer pathophysiology|Pathophysiology]]== |
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| *[[Smoking]]: Current smokers are several times more likely to develop anal cancer compared with nonsmokers.<ref name="ACS">American Cancer Society. [http://www.cancer.org/docroot/CRI/content/CRI_2_4_2X_What_are_the_risk_factors_for_Anal_Cancer_47.asp?sitearea "What Are the Risk Factors for Anal Cancer?"]</ref>
| | ==[[Anal cancer causes|Causes]]== |
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| *[[Immunosuppression]], which is often associated with [[HIV]] infection.<ref name="ACS">American Cancer Society. [http://www.cancer.org/docroot/CRI/content/CRI_2_4_2X_What_are_the_risk_factors_for_Anal_Cancer_47.asp?sitearea "What Are the Risk Factors for Anal Cancer?"]</ref>
| | ==[[Anal cancer differential diagnosis|Differentiating Anal cancer from other Disorders]]== |
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| ==Prevention== | | ==[[Anal cancer epidemiology and demographics|Epidemiology and Demographics]]== |
| Since many, if not most, anal cancers derive from [[Human Papilloma Virus]] infections, and since the [[HPV vaccine]] prevents infection by several strains of the virus, scientists surmise that HPV vaccination will prevent anal cancer. <ref>{{http://www.iht.com/articles/2007/01/31/healthscience/sncancer.php}}</ref>
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| ==Screening== | | ==[[Anal cancer risk factors|Risk Factors]]== |
| Anal [[pap smear]]s similar to those used in [[cervical cancer]] screening have been studied experimentally for early detection of anal cancer in high-risk individuals.<ref>Cichoki, Mark. [http://aids.about.com/cs/conditions/a/analpaps.htm "Anal Papilloma Screening"] on About.com</ref><ref>{{cite journal |author=Chiao EY, Giordano TP, Palefsky JM, Tyring S, El Serag H |title=Screening HIV-infected individuals for anal cancer precursor lesions: a systematic review |journal=Clin. Infect. Dis. |volume=43 |issue=2 |pages=223-33 |year=2006 |pmid=16779751 |doi=10.1086/505219}}</ref> | | |
| | ==[[Anal cancer screening|Screening]]== |
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| | ==[[Anal cancer natural history|Natural History, Complications and Prognosis]]== |
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| | ==Diagnosis== |
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| | [[Anal cancer staging | Staging]] | [[Anal cancer history and symptoms| History and Symptoms]] | [[Anal cancer physical examination | Physical Examination]] | [[Anal cancer laboratory studies | Laboratory Findings]] | [[Anal cancer MRI|MRI]] | [[Anal cancer CT|CT]] | [[Anal cancer ultrasound|Ultrasound]] | [[Anal cancer other imaging findings|Other imaging findings]] | [[Anal cancer other diagnostic studies|Other Diagnostic Studies]] |
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| ==Treatment== | | ==Treatment== |
| ===Localized disease===
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| Anal cancer is most effectively treated with surgery, and in early stage disease (i.e., localized cancer of the anus without [[metastasis]] to the [[inguinal]] [[lymph nodes]]), surgery is often curative. The difficulty with surgery has been the necessity of removing the [[anal sphincter]], with concomitant fecal [[incontinence]]. For this reason, many patients with anal cancer have required permanent [[colostomies]].
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| In more recent years, physicians have employed a combination strategy including [[chemotherapy]] and [[radiation treatments]] to reduce the necessity of debilitating surgery. This "combined modality" approach has led to the increased preservation of an intact anal sphincter, and therefore improved quality of life after definitive treatment. Survival and cure rates are excellent, and many patients are left with a functional sphincter. Some patients have fecal incontinence after combined [[chemotherapy]] and radiation. Biopsies to document disease regression after [[chemotherapy]] and radiation were commonly advised, but are not as frequent any longer. Current [[chemotherapy]] active in anal cancer includes [[cisplatin]] and [[5-FU]]; [[mitomycin]] has also been used, but is associated with increased toxicity.
| | [[Anal cancer medical therapy| Medical Therapy]] | [[Anal cancer surgery| Surgery]] | [[Anal cancer primary prevention| Primary Prevention]] | [[Anal cancer secondary prevention|Secondary Prevention]] | [[Anal cancer cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Anal cancer future or investigational therapies|Future or Investigational Therapies]] |
| ===Metastatic or recurrent disease===
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| Up to 10% of patients treated for anal cancer will develop distant metastatic disease. Metastatic or recurrent anal cancer is difficult to treat, and usually requires [[chemotherapy]]. Radiation is also employed to palliate specific locations of disease that may be causing symptoms. Chemotherapy commonly used is similar to other [[squamous cell]] [[epithelial]] [[neoplasms]], such as platinum analogues, [[anthracyclines]] such as [[doxorubicin]], and antimetabolites such as [[5-FU]] and [[capecitabine]].
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| ==Prognosis== | | ==[[Anal cancer case studies|Case Studies]]== |
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| | [[Anal cancer case Studies | Case Studies ]] |
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| == See also == | | ==[[Anal cancer related chapters|Related Chapters]]== |
| *[[Anal wart]]s | | *[[Anal wart]]s |
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| ==References== | | ==References== |
| {{reflist}} | | {{reflist|2}} |
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| == External links == | | == External links == |
| *[http://www.gaphr.org/AnalWarts.htm Anal Warts, Anal Cancer, and Anal Pap Smears]
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| *[http://www.lgbthealthchannel.com/msmcancer/ Anal Cancer and HPV in Men Who Have Sex With Men]
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| *[http://www.nci.nih.gov/cancertopics/pdq/treatment/anal/healthprofessional National Cancer Institute (U.S.): Anal Cancer: Information for Health Professionals] | | *[http://www.nci.nih.gov/cancertopics/pdq/treatment/anal/healthprofessional National Cancer Institute (U.S.): Anal Cancer: Information for Health Professionals] |
| *[http://www.plwc.org/anal People Living With Cancer (PLWC): Anal Cancer]
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| *[http://www.bidmc.org/YourHealth/ConditionsAZ.aspx?ChunkID=251634 Beth Israel Deaconess Medical Center: Anal cancer]
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| {{SIB}}
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| {{Tumors}} | | {{Tumors}} |
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| [[Category:Gastroenterology]]
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| [[Category:Types of cancer]]
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| [[Category:Oncology]]
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| [[fr:Cancer de l'anus]] | | [[fr:Cancer de l'anus]] |
| [[hu:Anális rák]] | | [[hu:Anális rák]] |
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| {{WikiDoc Help Menu}} | | {{WikiDoc Help Menu}} |
| {{WikiDoc Sources}} | | {{WikiDoc Sources}} |
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| | [[Category:Disease]] |
| | [[Category:Gastroenterology]] |
| | [[Category:Types of cancer]] |
| | [[Category:Oncology]] |
| | [[Category:Mature chapter]] |