World Library  
Flag as Inappropriate
Email this Article

Anal cancer

Article Id: WHEBN0000606777
Reproduction Date:

Title: Anal cancer  
Author: World Heritage Encyclopedia
Language: English
Subject: Human papillomavirus, HPV vaccines, Wart, Gastrointestinal cancer, Digestive system neoplasm
Collection: Gastrointestinal Cancer, Infectious Causes of Cancer, Papillomavirus-Associated Diseases
Publisher: World Heritage Encyclopedia

Anal cancer

Anal cancer
Diagram showing stage 1 anal cancer
Classification and external resources
Specialty Oncology
ICD-10 C21
DiseasesDB 31467
MeSH D001005

Anal cancer is a cancer (malignant tumor) which arises from the anus, the distal opening of the gastrointestinal tract. It is a distinct entity from the more common colorectal cancer.

Anal cancer is typically an anal squamous cell carcinoma that arises near the squamocolumnar junction, often linked to human papillomavirus (HPV) infection. It may be keratinizing (basaloid) or non-keratinizing (cloacogenic). Other types of anal cancer are adenocarcinoma, lymphoma, sarcoma or melanoma. From data collected 2004-2010, the relative five year survival rate in the United States is 65.5%, though individual rates may vary depending upon the stage of cancer at diagnosis and the response to treatment.[1]


  • Signs and symptoms 1
  • Risk factors 2
  • Pathology 3
  • Prevention 4
  • Screening 5
  • Treatment 6
    • Localised disease 6.1
    • Metastatic or recurrent disease 6.2
  • Epidemiology 7
    • US 7.1
    • UK 7.2
    • Worldwide 7.3
  • See also 8
  • References 9
  • External links 10

Signs and symptoms

Symptoms of anal cancer can include pain or pressure in the anus or rectum, a change in bowel habits, a lump near the anus, rectal bleeding, itching or discharge. Bleeding may be severe.[2][3]

Risk factors

  • Human papillomavirus: 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.[4] In another study done, high-risk types of HPV, notably HPV-16, were detected in 84 percent of anal cancer specimens examined.[5] Based on the study in Denmark and Sweden, Parkin estimated that 90% of anal cancers are attributable to HPV.[6]
  • [8] Those who engage in anal intercourse with multiple partners are 17 times more likely to develop anal cancer than those who do not.[9]
  • [8]
  • [7]
  • Benign anal lesions.[10][11]
  • A history of cervical, vaginal or vulval cancers[12]
  • Cloacogenic. Cloacogenic carcinoma is a rare tumor of the anorectal region originating from a persistant remnant of the cloacal membrane of the embryo. The tumor accounts for 2-3% of anorectal carcinomas and occurs more than twice as often in women.[13]


Most anal cancers are squamous cell carcinomas (epidermoid carcinomas), that arises near the squamocolumnar junction. It may be keratinizing (basaloid) or non-keratinizing (cloacogenic).

Other types of anal cancer are adenocarcinoma, lymphoma, sarcoma or melanoma.


Since many, if not most, anal cancers derive from HPV infections, and since the HPV vaccine before exposure to HPV prevents infection by some strains of the virus and has been shown to reduce the incidence of potentially precancerous lesions,[14] scientists surmise that HPV vaccination may reduce the incidence of anal cancer.[15]

On 22 December 2010, the U.S. Food and Drug Administration approved Gardasil vaccine to prevent anal cancer and pre-cancerous lesions in males and females aged 9 to 26 years. The vaccine has been used before to help prevent cervical, vulvar, and vaginal cancer, and associated lesions caused by HPV types 6, 11, 16, and 18 in women.[16]


Anal Pap smears similar to those used in cervical cancer screening have been studied for early detection of anal cancer in high-risk individuals.[17] In 2011, the HIV clinic at Jackson Memorial Hospital implemented a program to enhance access to anal cancer screening for HIV-positive men. Nurse practitioners perform anal Papanicolaou screening, and men with abnormal results receive further evaluation with high-resolution anoscopy. The program has helped identify many precancerous growths, allowing them to be safely removed.[18]


Localised disease

Localised disease (carcinoma-in-situ) and the precursor condition, anal intraepithelial neoplasia (anal dysplasia or AIN) can be ablated with minimally invasive methods such as Infrared Photocoagulation.[19]

Previously, anal cancer was treated with surgery, and in early stage disease (i.e., localised 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 internal and external anal sphincter, with concomitant fecal incontinence. For this reason, many patients with anal cancer have required permanent colostomies.

Current gold-standard therapy is chemotherapy and radiation treatment to reduce the necessity of debilitating surgery.[20] 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 consists of continuous infusion 5-FU over four days with bolus mitomycin given concurrently with radiation. 5-FU and cisplatin are recommended for metastatic anal cancer.

Metastatic or recurrent disease

10 to 20% of patients treated for anal cancer will develop distant metastatic disease following treatment.[21] 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. J.D. Hainsworth developed a protocol that includes Taxol and Carboplatinum along with 5-FU. Median survival rates for patients with distant metastases ranges from 8 to 34 months.[21]



The American Cancer Society estimated that in 2014 about 7,060 new cases of anal cancer would be diagnosed in the United States (4,430 in women and 2,630 in men) .[22] It is typically found in adults, average age early 60s.[22]

In the United States, an estimated 800 to 900 people die of anal cancer annually.[22]


Anal cancer accounts for less than 1% of all cancer cases and deaths in the UK. Around 1,200 people were diagnosed with the disease in 2011, and around 310 people died in 2012.[23]


Worldwide in 2002 there were an estimated 30,400 new cases of anal cancer.[6] With approximately equal fractions in the developing (15,900) and developed (14,500) countries.[6] An estimated 90% (27,400) were attributable to Human papillomavirus (HPV).[6]

See also


  1. ^ "SEER Stat Fact Sheets: Anal Cancer". NCI. Retrieved 22 December 2014. 
  2. ^ National Cancer Institute. Anal Cancer Treatment (PDQ) Patient Version. 13 June 2008. Accessed 26 June 2009.
  3. ^ Stanley, Margaret A; Winder, David M; Sterling, Jane C; Goon, Peter KC (2012). "HPV infection, anal intra-epithelial neoplasia (AIN) and anal cancer: current issues". BMC Cancer 12 (1): 398.  
  4. ^ Frisch M (August 2002). "On the etiology of anal squamous carcinoma". Danish Medical Bulletin 49 (3): 194–209.  
  5. ^ Frisch M, Glimelius B, van den Brule AJ; et al. (November 1997). "Sexually transmitted infection as a cause of anal cancer". N. Engl. J. Med. 337 (19): 1350–8.  
  6. ^ a b c d Parkin DM (2006). "The global health burden of infection-associated cancers in the year 2002". Int. J. Cancer 118 (12): 3030–44.  
  7. ^ a b c "Anal Cancer".  
  8. ^ a b c Changing Trends in Sexual Behavior May Explain Rising Incidence of Anal Cancer Among American Men and Women""Fred Hutchinson Cancer Research Center, .  
  9. ^ "STD Facts – HPV and Men". Archived from the original on 14 September 2007. Retrieved 2007-08-17. 
  10. ^ Natia Esiashvili, Jerome Landry, Richard H. Matthews (2007). "Carcinoma of the Anus Management". Armenian Health Network, Archived from the original on 5 February 2008. Retrieved 2008-01-22. 
  11. ^ Lin AY, Gridley G, Tucker M (January 1995). "Benign anal lesions and anal cancer". N. Engl. J. Med. 332 (3): 190–1.  
  12. ^ Abdulaziz, M (2011). "Risk of Anal Cancer in a Cohort With Human Papillomavirus–Related Gynecologic Neoplasm". Obstet Gynecol (117): 643–9. 
  13. ^
  14. ^ Gardasil, Merck's Cervical Cancer Vaccine, Demonstrated Efficacy in Preventing HPV-Related Disease in Males in Phase III Study: Pivotal Study Evaluating Efficacy of Gardasil in Males in Preventing HPV 6, 11, 16 and 18-Related External Genital Lesions".""". Merck Research and Development News. ( Archived from the original on 15 December 2008. Retrieved 2008-11-15. 
  15. ^ Tuller, David (2007-01-31). "HPV vaccine may help to prevent anal cancer". International Herald Tribune. Retrieved 2014-12-22. 
  16. ^ US approves anal cancer vaccine
  17. ^ Chiao EY, Giordano TP, Palefsky JM, Tyring S, El Serag H (2006). "Screening HIV-infected individuals for anal cancer precursor lesions: a systematic review". Clin. Infect. Dis. 43 (2): 223–33.  
  18. ^ "Hospital HIV Clinic Offers Convenient, Proactive Screening for Anal Cancer, Enabling Identification and Treatment of Precancerous Lesions". Agency for Healthcare Research and Quality. 2013-04-10. Retrieved 2013-05-10. 
  19. ^ Goldstone, SE, Kawalek, AZ, Huyett, JW "Infrared Photocoagulator: A useful tool for treating anal squamous intraepithelial lesions". 2005. Diseases of the Colon & Rectum 58(5), 1042–1053.
  20. ^ National Comprehensive Cancer Network. "NCCN Clinical Practice Guidelines in Oncology: Anal Carcinoma. V 1.2013" (PDF). 
  21. ^ a b "Metastatic Squamous Cell Carcinoma of the Anus: Time for a Shift in the Treatment Paradigm?". PubMed Central (PMC). 
  22. ^ a b c "Detailed Guide: Anal Cancer What Are the Key Statistics About Anal Cancer?". Archived from the original on 10 October 2008. Retrieved 2008-11-18. 
  23. ^ "Anal Cancer Statistics". Cancer Research UK. Retrieved 27 October 2014. 

External links

  • American Cancer Society – Detailed Guide: Anal Cancer
  • Anal Warts, Anal Cancer, and Anal Pap Smears
  • Anal Cancer and HPV in Men Who Have Sex With Men
  • Clinically reviewed anal cancer information for patients, from Cancer Research UK
  • National Cancer Institute (U.S.): Anal Cancer: Information for Health Professionals
  • Cancer.Net: Anal Cancer
  • The HPV and Anal Cancer Foundation
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.