Anal cancer

Peer reviewed by Mr Simon M Phillips, Consultant Colorectal Surgeon
Next review due: June 2019

Anal cancer is a growth (tumour) that’s created when cells in your anus grow in an abnormal and uncontrolled way.

Anal cancer is rare – only about 500 people are diagnosed with it each year in the UK. But this number has been rising in recent years, particularly in women.

Types of anal cancer

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.

There are different types of anal cancer. Squamous cell carcinoma is the most common type. This develops from small flat cells that line your anal canal.

Other rarer types of anal cancer include the following.

  • Adenocarcinoma, which develops from the cells that produce mucus within your anal canal.
  • Malignant melanoma, a type of cancer that starts in cells called melanocytes and which you can get around your anus. Melanocytes are a type of cell found in your skin.

Symptoms of anal cancer

Symptoms of anal cancer include:

  • bleeding from your bottom, which you may see in your faeces or notice on toilet paper
  • pain in your bottom
  • discharge coming out from your bottom
  • small lumps or ulcers around the area
  • feeling itchy around your bottom area
  • difficulty controlling your bowel movements, which is called faecal incontinence
  • a change in your bowel habits – you may go more often, for example

These symptoms might not be caused by anal cancer, but if you have them, contact your GP.

Diagnosis of anal cancer

Your GP will ask about your symptoms and examine you. They’ll ask about your medical history too.

Your GP may examine your rectum. They’ll need to feel inside your bottom with their finger to do this (they’ll wear a glove and use lubrication). Although it might feel a little uncomfortable, it shouldn’t be painful. If you’re a woman, your GP may also need to examine you this way inside your vagina to check for a tumour pressing through.

If your GP suspects you have anal cancer, they'll refer you to see a doctor who specialises in conditions that affect the bowel. The specialist or your GP may arrange for you to have further tests to examine your bowel. This might include a proctoscope or sigmoidoscopy test, which involves using a narrow tube to look at the inside of your rectum and large bowel. Your doctor may take a small sample of tissue (a biopsy) during the test. They’ll send this to a laboratory for testing to find out whether the cells are cancerous or not.

If you’re found to have anal cancer, you may need to have some other tests to find out how advanced it is. This process is known as staging. 

Treatment of anal cancer

Your treatment will depend on the type of anal cancer you have, and how far it’s spread. Your doctor will discuss what your options are.

Non-surgical treatments

The most common treatment for anal cancer is a combination of chemotherapy and radiotherapy, which is called chemoradiotherapy. Chemotherapy uses medicines to destroy cancer cells and radiotherapy uses radiation. You may have these treatments on the same day. For more information on chemoradiation, see the FAQ: What’s chemoradiotherapy?


Your doctor may also recommend you have surgery to remove your cancer. The operation you’re offered will depend on the size and position of your tumour.

Local excision

If your tumour is small, you might be able to have an operation called a local excision. This will remove the affected area and it shouldn't affect how you go to the toilet – you can still pass faeces.

Abdominoperineal resection (AP resection)

This involves removing your anus, rectum and part of your bowel. The end of your bowel will then 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’ll need to wear a bag over your stoma, which will collect faeces outside your body.

Usually, you'll only need to have this type of surgery if your cancer hasn't responded to chemoradiotherapy.

It may take a while to adjust to living with a stoma, but you can get help and advice from your doctor or stoma nurse. See Related information for more tips on how to live with a stoma.

Causes of anal cancer

Doctors don’t yet know the exact reasons why people develop anal cancer, but some things make you more likely to develop it. These include the following.

  • Certain types of human papilloma virus (HPV) can affect your chances of getting anal cancer. Around eight in 10 people diagnosed with anal cancer have an HPV infection. You’re also more likely to get it if you’ve had genital warts, or vaginal or cervical cancer, which are associated with the HPV virus.
  • Having anal sex (particularly men having sex with men), and having sex with many partners also increases your risk of getting anal cancer.
  • Your age – anal cancer is most common in people over 55.
  • Your gender – anal cancer is more common in women.
  • Smoking.
  • A weakened immune system, which can happen if you have HIV/AIDS or take medicines that suppress your immune system. 

Prevention of anal cancer

There are some things you can do to reduce your risk of getting anal cancer. These include:

  • not smoking
  • using condoms when you have sex, and limiting the number of sexual partners you have in order to lower your chances of getting HPV

Frequently asked questions

  • Yes. You can still do most sports and activities, and can even go swimming if you have a colostomy.

    There’s no reason why your lifestyle shouldn’t be as active as it was before you had your colostomy. There’s a range of different stoma appliances you can use for swimming and other activities, such as waterproof bags and seals. Talk to your doctor or stoma nurse before you do any contact sports as these could injure your stoma. But that said, it may still be possible because you can get protective stoma shields. 

  • Yes, there are lots of other conditions that can cause symptoms similar to those of anal cancer. Many are not cancer and are easily treated.

    One symptom of anal cancer is bleeding from your rectum. This can happen if you get a small tear in the lining of your anal canal, called an anal fissure. Rectal bleeding can also be caused by piles (haemorrhoids), which feel like small lumps around your anus that can be itchy.

    If you’re worried about your symptoms, contact your GP.

  • Chemoradiotherapy is when you have chemotherapy and radiotherapy alongside each other. Chemotherapy for anal cancer will usually be given to you through a drip that will be placed into a vein in your arm. Radiotherapy uses high-energy X-rays produced by a machine.

    More information

    Your treatment plan will be tailored to your needs. You’ll usually have chemotherapy over four days, and will have two cycles, with a break of about four weeks between the two.

    Radiotherapy treatment usually starts on the same day as chemotherapy. It’s a short treatment that you may have once every weekday for around five weeks. You can usually have radiotherapy as an out-patient, which means you have the treatment in hospital but won't need to stay overnight. Speak to your specialist doctor or nurse if you’d like more information.

  • Your digestion may take some time to settle down after your treatment for anal cancer. It might help to make some changes to your diet during this time.

    More information

    Having radiotherapy can irritate your rectum (back passage) and you might get diarrhoea. You’ll probably feel really tired and may feel sore around your bottom. It might be particularly painful when you go to the toilet. If this happens, let your nurse or doctor know. They can give you some painkillers and advice on how to care for the skin around the area.

    It might help to eat less fibre during and after your treatment. Fibre is found in fruit and vegetables, as well as other foods such as oats, rice and pasta. Once your digestion has settled down again, you can gradually reintroduce more fibre to your diet. You might also need to make some changes to your diet if you have a colostomy. See Related information for more information about how to take care of a stoma.

  • After you've finished your treatment, you’ll need to have regular check-ups with your doctor.

    More information

    You’ll need to see your doctor for regular appointments after your treatment has finished. They'll check if your cancer has come back, or spread to other parts of your body. Your doctor will usually need to examine your anus in these appointments. You may occasionally need to have:

    • a proctoscope or sigmoidoscope test, which involves using a narrow tube to look at the inside of your rectum and large bowel
    • a rectal ultrasound (where a small probe will be passed into your anus)
    • an MRI scan
    • a CT scan

    If you get any symptoms between your scheduled check-ups, it's important to see your doctor as soon as possible.

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Related information

    • Anal cancer. BMJ Best Practice., last updated 28 April 2016
    • Colorectal disease. ACPGBI position statement for management of anal cancer. Association of Coloproctology of Great Britain and Ireland, published 13 February 2011
    • Anal canal anatomy. Medscape., updated 25 February 2015
    • Anal cancer. Cancer Research UK., updated 7 February 2014
    • Glynne–Jones R, Nilsson PJ, Aschele C, et al. Anal cancer: ESMO-ESSO-ESTRO clinical practice guidelines for diagnosis, treatment and follow-up. Eur J Surg Oncol 2014; 40(10):1165–76
    • Rectal examination. PatientPlus., last checked 24 November 2014
    • Anal carcinoma. PatientPlus., last checked 19 July 2012
    • Anal cancer. American Society of Colon and Rectal Surgeons., published August 2015
    • Dietary fibre. British Nutrition Foundation., last reviewed June 2014
    • Anal fissure. NICE Clinical Knowledge Summaries., last revised July 2016
    • Haemorrhoids. NICE Clinical Knowledge Summaries., last revised September 2012
    • Stoma care. PatientPlus., last checked 15 July 2014
  • Reviewed by Rachael Mayfield-Blake, Freelance Health Editor, Bupa Health Content Team, June 2016
    Peer reviewed by Mr Simon M Phillips, Consultant Colorectal Surgeon
    Next review due: June 2019

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