Your anus is the area at the very end of your bowel. Your anal canal is the tube that connects the lower part of your large bowel (rectum) to the outside of your body. It's surrounded by a muscle called the anal sphincter, which relaxes and contracts to control your bowel movements.
There are a number of types of anal cancer.
Anal cancer is a rare form of cancer - about 930 people are diagnosed with this type of cancer each year in the UK. However, this number has been rising in recent years, particularly in women.
Symptoms of anal cancer include:
These symptoms aren't always caused by anal cancer but if you have them, contact your GP.
Around one in five people with anal cancer don't have any symptoms.
The reasons why you may develop anal cancer aren't fully understood at present. The following factors may increase your chance of getting the disease.
Your GP will ask about your symptoms and examine you. He or she may also ask about your medical history.
Your GP may do a rectal examination, which involves inserting his or her finger inside your anus (he or she will wear a glove and use lubrication). Although a little uncomfortable, this isn't painful.
Your GP may refer you to a colorectal surgeon (a doctor who specialises in conditions that affect the bowel). He or she may use a proctoscope or sigmoidoscope to examine the area more carefully. These are narrow tubes with a light that allows your surgeon to examine the lining of your anus and rectum and if necessary, take a biopsy. A biopsy is a small sample of tissue. This will be sent to a laboratory for testing to find out whether the cells are malignant (cancerous) or benign (not cancerous). In some GP practices, these tests may be carried out by your GP.
If these tests show that you have anal cancer, you will have more tests to see how big your cancer tumour is and whether it has spread to other parts of your body. These might include:
There are several different types of treatment for anal cancer, depending on how big your cancer tumour is and whether it has spread.
The most common form of treatment for anal cancer is a combination of chemotherapy and radiotherapy. This is known as chemoradiation. These treatments may be given to you at the same time or following one another.
Chemotherapy uses medicines to destroy cancer cells.
Radiotherapy uses X-rays to destroy cancer cells. Occasionally internal radiotherapy (brachytherapy) may be used, which involves your doctor temporarily placing radioactive wires around the tumour area.
Surgery is often used to treat anal cancer if non-surgical treatments, such as chemoradiation, haven’t worked.
There are two types of surgery that can be used to remove anal cancer. The operation you have will depend on the size and position of your tumour.
An operation called a local resection is used to remove small tumours and some of the surrounding tissue. This type of surgery usually doesn't affect your ability to pass a bowel movement.
Alternatively, if other surgical or non-surgical treatments have failed, a more extensive operation may be required. This is called an abdominoperineal resection (AP resection) and involves removing your anus, rectum and part of your bowel. Without your rectum and anus you won't be able to pass a bowel movement, so the end of your bowel will be brought out onto the skin on the surface of your abdomen. This is called a colostomy and the opening of your bowel is known as a stoma. You will wear a bag over your stoma, which will collect faeces outside your body. It may take a while to adjust to living with a stoma, but people with colostomies are able to live normal lives.
One way to reduce your risk of getting anal cancer is to avoid getting HPV, which is passed through sexual contact. It's important to remember that you can have HPV but not have genital warts or any other symptoms.
To reduce your risk of HPV infection:
If you smoke, try to stop as this will reduce your risk of getting anal cancer. If you're having trouble giving up, contact your GP for advice.
Produced by Kerry McKeagney, Bupa Health Information Team, June 2012.