What is Anal Cancer?

The Causes, Symptoms, Treatment, and Prevention of Anal Cancer

The anus is located at the opening of the rectum. Ericsphotography/Getty Images

Anal cancer is cancer that develops in the anus, the opening of the rectum, which allows waste to pass from the large intestine to outside of the body. The anus is often confused with the rectum, which is the last several inches of the lower intestine. The rectum ultimately ends at the anus, where fecal material exits the body.

Like other parts of the body, the anus is susceptible to infections and diseases, such as anal cancer.

Anal Cancer Causes and Risk Factors

  • smoking cigarettes
  • infection with HPV virus
  • receiving anal intercourse
  • abnormal openings in or around the anus (fistulas)
  • having multiple sexual partners
  • being older than 50 years of age
  • anal swelling, redness or soreness that occurs frequently

Anal Cancer Symptoms

The symptoms of anal cancer are not unique and are also symptoms of other conditions, such as hemorrhoids. Although anal cancer is relatively simple to diagnose, this can cause a delay in diagnosis for some with anal cancer.

Symptoms of anal cancer include:

  • lumps or bumps located near the anus
  • anal bleeding or bleeding during bowel movements
  • anal discharge
  • pain in or around the anus
  • itchy sensation around or inside the anus
  • change in bowel habits, such as constipation, diarrhea and thinning of the stools

Diagnosis of Anal Cancer

Symptoms are most often what prompt people to seek medical attention that leads to an anal cancer diagnosis, but sometimes the cancer is found through a routine digital rectal exam or an anal Pap test.

If anal cancer is suspected, then further evaluation is required to confirm the presence or absence of cancer.

The first step in diagnosing cancer is to view the anus and rectum more closely. This is done endoscopically, with a hollow, lighted tube called "anoscope." The anoscope is lubricated and inserted into the anus, allowing the doctor to get a better view of the anus.

The procedure is called an "anoscopy" and is brief and painless.

If a suspicious area is found during an anoscopy, then the doctor may remove it or do a biopsy. A biopsy involves removing small samples of abnormal tissue to be later viewed under a microscope by a pathologist.

The pathologist studies the biopsy and looks for cancerous cells. If cancer is confirmed, then he or she will also determine what stage the anal cancer has progressed to. Staging refers to how far the cancer has spread to nearby tissues. For those with suspected cases of advanced anal cancer, more tests may be done to determine the anal cancer stage. Tests may include MRIs, CT scans or other imaging tests.

Anal Cancer Treatment

There are three primary methods of treating anal cancer: radiation therapy, chemotherapy and surgery.

Radiation Therapy. Radiation therapy uses certain types of high-energy beams of radiation to shrink tumors or eliminate cancer cells. Radiation therapy works by damaging a cancer cell's DNA, making it unable to multiply. Although radiation therapy can damage nearby healthy cells, cancer cells are highly sensitive to radiation and typically die when treated. Healthy cells that are damaged during radiation are resilient and are often able to fully recover.

Two primary types of radiation therapy are external beam radiation therapy and internal beam radiation, also called "brachytherapy." External beam radiation is much more common than internal beam radiation in treating anal cancer.

Chemotherapy. Chemotherapy may be prescribed to treat anal cancer in conjunction with radiation therapy treatments. Chemotherapy drugs work by eliminating rapidly multiplying cancer cells, however, there are other healthy cells in the body that multiply just as quickly, such as hair follicle cells.

Unfortunately, many chemotherapy drugs may not be able to discern the two, attacking healthy cells and causing side effects, such as hair loss.

Surgery. Surgery to remove the tumor is the least common method of treating anal cancer but is still an option for some. When surgery is recommended, it is often done in conjunction with radiation therapy and/or chemotherapy.

Anal Cancer Prevention

Since we cannot explain what exactly causes anal cancer, total prevention can be difficult. The best defense we have against developing the disease is to avoid the known risk factors. Tips to help reduce your risk of anal cancer include:

Using a condom during intercourse. Wearing a condom may provide protection against HPV. Although condoms do not provide 100% protection against HPV, you are much safer wearing one than not.

Limiting the amount of sexual partners you have. When a person has multiple sexual partners, they are at an increased risk for HPV, which is linked to anal cancer.

Avoiding anal intercourse. Anal intercourse increases the risk factor for anal cancer for both men and women.

Quitting smoking. According to the American Cancer Society, smokers are 4 times more likely to develop anal cancer than nonsmokers. Smoking also puts you at a higher risk for many other types of cancer.

The HPV vaccine is expected to reduce cases of anal cancer, but there are no studies that confirm this yet. Gardasil, the current FDA-approved vaccine, is available to young women ages 9 to 26. It provides protection against two strains of HPV known to cause cervical cancer in women and two strains that cause genital warts also. Because these strains of HPV may be related to the development of anal cancer, the vaccine may provide protection. More research is being done to study the vaccine's efficacy in men.


"Can Anal Cancer Be Found Early?". Detailed Guide: Anal Cancer. American Cancer Society. 25 April 2007.

"What is Anal Cancer?". Detailed Guide: Anal Cancer. American Cancer Society. 25 April 2007.

Continue Reading