Reviewed December 2011
This information should not be used to self-diagnose, or be used in place of a qualified physician’s care.
- Patients with anal cancer are treated by members of the BC Cancer Agency’s Gastrointestinal (GI) Tumour Group.
- For healthcare professional information on treating this cancer, please see our Cancer Management Guidelines.
- The anus or anal canal is the tube that connects the rectum to the outside of the body.
- Anal cancer is not common. There are about 600 cases in Canada each year.
- The incidence of anal cancer is rising for women.
- Anal cancer can be cured in most cases.
What causes it and who gets it?
Listed below are some of the known risk factors for this cancer. Not all of the risk factors below may cause this cancer, but they may be contributing factors.
- The cause of anal cancer is unknown.
- The following contributing factors are recognised:
- HPV (human papillomavirus) infections
- Anal sex
- Having many sexual partners
- HIV (human immunodeficiency virus)
- Bowen’s disease is a skin condition (a rough, scaly patch) that can occur in the skin around the anus. It can become cancer if left untreated
- BC Statistics (2009)
- 88 new cases diagnosed – 55 female, 33 male
- 21 deaths – 11 female, 10 male
- See graphs, or scroll to the bottom of the page.
Can I help to prevent it?
- Avoid anal sexual intercourse
- Use a condom, which can protect against HIV, but will not fully protect against HPV (human papilloma virus)
- Don’t smoke
Screening for this cancer
- No general screening program is effective for anal cancer.
- If symptoms occur, physical examination by a doctor is effective for detecting anal cancer.
- People at higher risk for anal surface cancers (intraepithelial neoplasia) may benefit from a test of cells scraped from the anus. These people include homosexual men, women who have had cervical or vulvar cancer, HIV-positive men and women and transplant recipients.
Signs and Symptoms
- In the earlier stages, there may be no symptoms. The following symptoms must be checked by your doctor:
- Bleeding from the anus often occurs and may be the first sign
- Persistent anal itching
- Discharge of mucus from the anus
- A change in bowel movements
- A sore that is on or near the anus
- Swollen lymph nodes in the groin or anal region
This is a list of some or all of the tests used to diagnose this type of cancer.
- Physical examination
- Digital rectal examination (DRE)
- Anoscopy or proctoscopy, which is the insertion of a tube into the anus with a light to allow viewing of the interior of the anal canal.
- Biopsy of anal tissue – a small bit of the suspicious tissue is removed and examined by a pathologist.
- If lymph nodes are swollen, it may be possible to test for the presence of cancer cells.
- If cancer is found, further tests are done to determine the spread of the disease. These include a CT scan of the abdomen and pelvis, an ultrasound to examine the liver and an MRI to assess the pelvis.
- For more information on all cancer diagnostic tests, see our Recommended Websites, Diagnosis section.
Types and Stages
Staging describes the extent of a cancer. The TNM classification system is used as the standard around the world. In general a lower number in each category means a better prognosis. The stage of the cancer is used to plan the treatment.
- T describes the site and size of the main tumour (primary);
- N describes involvement of lymph nodes;
- M relates to whether the cancer has spread (presence or absence of distant metastases).
- Almost all anal cancers are squamous cell carcinomas, which start in the cells that line the anus.
- The rest are cloacogenic (basaloid transitional).
- Adenocarcinomas are the rarest and develop in anal ducts and glands.
- Very rarely, basal cell carcinomas and melanomas develop in the anus.
|| Carcinoma in situ.|
|| Tumour is 2 cm or less.|
|| Tumour is between 2 cm - 5 cm.|
|| Tumour is more than 5 cm.|
|| Tumour of any size invades adjacent organ(s), e.g. vagina, urethra, bladder.|
Cancer therapies can be highly individualized – your treatment may differ from what is described below.
- If the tumour is small and near the anus, surgery is used to remove it completely. The function of the anus and bowel should be retained.
- If the tumour is larger or further into the anus, radiotherapy is used alone. It is expected to cure the cancer and retain the function of the bowel, but it does cause some side effects.
- For larger anal cancers, a combination of chemotherapy and radiation therapy offers a good chance of curing the cancer. Side effects from this treatment are more severe. The treatment tries to maintain the patient’s ability to have normal bowel movements.
- For the largest anal cancers, or those which do not respond to treatment, or if the cancer comes back after treatment, it may be necessary to remove the entire rectum and the patient will have a permanent colostomy.
Follow-up after Treatment
- Guidelines for follow-up after treatment has ended have been developed by the BC Cancer Agency and are listed on our website.
- You will be returned to the care of your family physician or specialist for regular followup.
- Follow-up testing is based on your type of cancer and your individual circumstances.
- The BCCA Survivorship Research Centre focusses on the issues that cancer survivors can face.
Coping with Cancer
The Coping with Cancer section of our website is a joint project among different BC Cancer Agency departments and programs. This website section provides information and links that can help cancer patients with the physical, emotional, psychological and practical aspects of care. Each cancer experience is different, but in one way or another, many cancer patients share the same needs.
The effects of cancer and its treatment can present unique challenges: from practical concerns like money and housing, to emotional concerns like anxiety and grief. If you need support with the practical and emotional impacts of cancer, or in managing symptoms and side effects you can use the information in Coping with Cancer to connect to these resources.
Search our library catalogue
- The BC Cancer Agency Library has many resources about cancer, coping, talking to children, etc. Please visit the Library in your Centre, call a librarian, or visit the Library online to see the many resources available.
The BC Cancer Agency has selected and evaluated these useful websites for your further information.
Websites for cancer survivors, and how to stay healthy after treatment.
View videos on cancer-related topics that the BC Cancer Agency produces.
How can I help with research at the BC Cancer Agency?
BC Cancer Agency patients are very helpful when it comes to the fight against cancer. Here are a few ways that you can help.
Anal Cancer in British Columbia - graphs
This information has been reviewed and approved by a member of the Gastrointestinal (GI) Tumour Group.