Revised February 2014
This information should not be used for self-diagnosis or in place of a qualified physician’s care.
- Guidelines for treating this cancer have been developed by the Gastrointestinal (GI) Tumour Group.
- For health 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?
Some of the known risk factors for this cancer are listed below. 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 infections (human papillomavirus)
- Anal sex
- Having many sexual partners
- HIV infections (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 from 2011
- 109 new cases diagnosed – 68 female, 41 male
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
- The anal canal should be examined by digital rectal examination (DRE) during a yearly physical exam.
- Persons at higher risk for anal cancer may benefit from a test of cells scraped from the anus.
Signs and Symptoms
- In the earlier stages, there may be no symptoms.
- The following symptoms should 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
These are tests that may be used to diagnose this type of cancer.
- Physical examination
- Digital rectal examination (DRE)
- Anoscopy or sigmoidoscopy, 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.
- Female patients should have a gynecological exam with pap smear to exclude cervical cancer, as both types of cancer are related to HPV (human papilloma virus).
- 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 tests used to diagnose cancer, see our Recommended Websites, Diagnosis section.
Types and Stages
- 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.
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).
|| 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 the sphincter is not involved, surgery is used to remove it completely. The function of the anus and bowel should be retained.
- If the tumour is small, but the sphincter is involved, radiation therapy may be used alone or in combination with chemotherapy.
- 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 are covered on our website.
- You will be returned to the care of your family physician or specialist for regular followup. If you do not have a family physician, please discuss this with your BC Cancer Agency oncologist or nurse.
- 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.
Living with Cancer
We know that cancer and its treatment can present unique challenges: from everyday concerns like diet, money and housing, to emotional concerns. The needs of our patients and their families and friends can be very diverse. Please explore this very useful part of our website. Here is some of what's included in this section:
- Coping with cancer
- Emotional support - cancer and the family, dealing with emotions, work and school-related issues, etc.
- Practical and financial support - home care, gov't. programs for assistance, travel, lodging, prescription drugs, etc.
- Nutritional support - poor appetite, taste changes, eating healthy, etc.
- Symptoms and side effects
- Palliative care
- The BC Cancer Agency Library has many resources about cancer, coping, talking to children, and more. Please visit the Library in your Centre, call a librarian, or visit the Library online to see the many resources available.
- Library Pathfinders are a good starting point for resources on types of cancer and living with cancer. They list books, videos, pamphlets, websites and support services.
The BC Cancer Agency has selected and evaluated these useful websites for your further information.
Colostomy / Urostomy / Ileostomy
Websites for cancer survivors, and how to stay healthy after treatment
VideosView BC Cancer Agency videos on cancer-related topics.
How can I help with research at the BC Cancer Agency?
Patients play a vital role in research to fight cancer. Here are a few ways you can help:
This information has been reviewed and approved by a member of the Gastrointestinal (GI) Tumour Group.