anal canal, anal verge, dentate line, anorectal line, perianal skin, rectum, colorectal zone, columnar epithelium, transitional zone, squamous zone, stratified epithelium
Anal Canal Anatomy

What is anal cancer?

Anal cancer is the term for abnormal cell growth in the anal area or the anal canal. The anal canal connects the anus (the opening) to the rectum. This passage is about 1-2 inches long. It is the part of the body that excretes solid waste (bowel movements, feces). The disease also is called carcinoma of the anal canal.

The anus is the end of the digestive system. The anus is made up of tissue from the skin and from the intestine. While not the only type of anal cancer, the most common type is squamous cell carcinoma (SCC), a type of skin cancer.

How common is anal cancer?

The American Cancer Society has predicted that there will be about 8,300 new cases of anal cancer in 2019. Females will account for about 5,530 of these cases. The organization estimates deaths at 1,280, with women representing 760 of the total. The number of cases of anal cancer has been on the rise in the past several years.

Who does anal cancer affect?

The risk of anal cancer is higher in women than in men. The general risk of getting anal cancer is about 1 in 500-600 people.

What are the risk factors for anal cancer?

The term “risk factor” refers to a thing that makes it more likely that you will get a disease. For anal cancer, risk factors include:

  • Human papilloma virus (HPV) infection. There are many types of HPV, which also causes genital warts. Some types of the virus are more likely to be linked with cancer of the anus, of the genitals, and certain head and neck cancers. Women who have cancer of the vulva, vagina or cervix have a higher risk of anal cancer.
  • Being infected with the human immunodeficiency virus (HIV).
  • Immunosuppression.
  • Urogynecological HPV disease
  • Engaging in anal sex as the receiving partner. This is true for both men and women. In general, having several partners for any type of sex increases the risk for getting HPV, HIV and anal cancer.
  • Oral HPV disease.
  • Getting older. The majority of anal cancer diagnoses are made in people who are 55 years old or older.
  • Using tobacco.
  • Having an impaired immune system due to disease or medication use. (For instance, people who are organ recipients must take medicine to prevent organ rejection.)
  • Having an abnormal opening, called a fistula, which goes from the anus to the skin around the anus or occasionally to another place in the body.

What causes anal cancer?

It is believed that human papilloma virus (HPV) is a cause of anal cancer. However, having HPV does not mean you will definitely have anal cancer. This is true for the other risk factors as well: none of them mean that you will definitely develop anal cancer, but having them does increase the risk.

What are the symptoms of anal cancer?

About a quarter of the people who have anal cancer do not notice any symptoms. When present, symptoms may include:

  • Bleeding from anus/rectum, especially during bowel movements
  • Having a lump or pain in the area
  • Itching (also known as pruritus)
  • Seeing a change in bowel movements, such as frequency or consistency of the stools
  • Leaking stool
  • Feeling like you constantly need to have a bowel movement

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