What is anal cancer?
Anal cancer is a cancer that starts in the anus. The anus is the opening at the end of the large bowel, which is part of the digestive system. It is where you pass poo (stools) out of the body. It is part of the large bowel which includes the colon and rectum.
We have more information about other types of bowel cancer including:
Clinical Oncologist Katherine Aitkens explains bowel cancer (which includes anal cancer), giving an overview of bowel cancer symptoms, diagnosis and treatment.
In the UK, about 1,500 people develop anal cancer each year. It is a rare cancer. But the number of people being diagnosed with anal cancer is increasing – especially women and people assigned female at birth. Anal cancer is much more common in women than in men and people assigned male at birth.
There are different types of anal cancer. Knowing the type you have helps your doctor plan your individual treatment.
Most anal cancers develop in the squamous cells which make up the lining of the anal canal. The information on this page is about squamous cell cancer of the anus.
Related pages
Booklets and resources
Symptoms of anal cancer
The most common symptoms of anal cancer are:
- bleeding from the anus
- pain
- itching or discomfort around the anus.
We have more information about the symptoms of anal cancer.
Related pages
Causes and risk factors of anal cancer
Doctors do not know the exact causes of anal cancer. But there are risk factors that can increase your chance of developing it.
Most anal cancers are caused by the human papillomavirus (HPV), a common virus that is passed on through sexual contact. Most people have HPV at some point and never know they have had it. The immune system usually gets rid of HPV. But a small number of HPV infections eventually lead to cancer developing.
We have more information about causes and risk factors of anal cancer.
Diagnosis of anal cancer
If you have symptoms, you will usually begin by seeing your GP, who will examine you. They may do the following tests::
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Rectal examination
A rectal examination is when the doctor gently inserts a gloved, lubricated finger into your back passage (rectum) to feel for any lumps or swellings. This may be uncomfortable, but it does not take long. Tell your GP if it is painful because it is important to tell the hospital specialist.
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Blood test
You may have blood tests. This is to check for anaemia, which is a low number of red blood cells. Blood tests also check how well your liver and kidneys are working.
Your GP will refer you to a hospital specialist. This is usually either a surgeon or a specialist in bowel conditions (gastroenterologist).
If your GP thinks you might have cancer, they will arrange for you to have an appointment at the hospital as quickly as possible.
At the hospital
At the hospital, the specialist will ask you about:
- your general health
- any previous medical problems
- whether you have a family history of cancer.
They may also ask some personal questions. These are to find out whether you have any risk factors linked with anal cancer, such as the HPV.
The specialist will feel your tummy. They might examine your anus and back passage by doing another rectal examination.
Sometimes they do an internal examination of the vagina. This is because it is close to the anal canal.
The specialist will examine the lymph nodes in your groin, as they are closest to the anus. If they are swollen, you may have further tests to check whether there is cancer in the lymph nodes.
The specialist will talk to you about the tests you need to have.
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Anal examination and biopsy
You may have an anal examination and biopsy taken. A specialist will examine the anal canal using a thin tube called an endoscope that has a light and camera on the end.
A biopsy is where the doctor removes a small sample of cells from any abnormal areas, so they can be examined under a microscope. You usually have this under general anaesthetic.
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Fine needle aspiration (FNA) of the lymph nodes
You may have this test to see whether cancer cells are in the lymph nodes. The doctor passes a fine needle into the lymph nodes and withdraws (aspirates) some cells into a syringe. This might feel a little uncomfortable, but it is very quick. You do not usually need to have a local anaesthetic. You might have an ultrasound scan at the same time to help guide the needle.
Further tests for anal cancer
If the biopsy shows you have anal cancer, you will need further tests. These are done to find out more about the position of the cancer and whether it has spread. You will usually have a scan to find out more about the cancer. You may have any of the following:
Waiting for test results can be a difficult time. We have more information that can help.
Related pages
Staging and grading of anal cancer
The results of your tests help your doctors find out more about the size and position of the cancer and whether it has spread. This is called staging.
A doctor decides the grade of the cancer by how the cancer cells look under the microscope. This gives an idea of how quickly the cancer might grow or spread.
Knowing the stage and grade of the anal cancer helps the doctors decide on the best treatment for you.
Treatment for anal cancer
A team of specialists will meet to discuss the best possible treatment for you. This is called a multidisciplinary team (MDT).
Your doctor, cancer specialist or nurse will explain the different treatments and their side effects. They will also talk to you about things to consider when making treatment decisions.
The treatment you have depends on the stage of the cancer. It also depends on your general health and preferences.
The main treatment for anal cancer is chemoradiation. This is when you have chemotherapy and radiotherapy together. Some people have these treatments on their own. Or you may have surgery to remove the cancer.
It is important to talk about your treatment options with your doctor. They can explain why they are suggesting a certain treatment plan and how the treatment may affect you.
Treatment for anal cancer can include:
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Chemoradiation
The main treatment for anal cancer is chemoradiation. This is when you have radiotherapy and chemotherapy together. Radiotherapy treats cancer by using high-energy rays that destroy cancer cells. Chemotherapy uses anti-cancer drugs to destroy cancer cells. It makes radiotherapy work better. Chemoradiation is usually successful. It also means you may avoid having a stoma. Most people do not need surgery after it.
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Surgery
Surgery is not often used to treat anal cancer. This is because chemoradiation is often the only treatment needed. You may be offered surgery if you have a very small tumour in the anal margin. This will only be if the surgeon can remove it without affecting how you pass poo (stools).
Some people may need a temporary or sometimes a permanent colostomy (stoma) after surgery. This is an opening the surgeon makes through the tummy (abdominal) wall. It connects the bowel to the surface of the tummy.
We have more information about surgery for anal cancer.
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Radiotherapy
You may have radiotherapy on its own if you are not well enough to have chemoradiation. Radiotherapy can also be used to help with symptoms if the cancer has spread.
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Chemotherapy
You may have chemotherapy on its own if the cancer has spread to other parts of the body. It may help to control the cancer and improve symptoms.
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Clinical trials
Your cancer doctor may invite you to take part in a clinical trial.
After anal cancer treatment
Follow up after treatment for anal cancer
After treatment has finished, you will have regular check-ups every few months for the first 2 years. These usually continue for up to 5 years. You have them less often as time goes on.
At your check-ups, a specialist doctor will:
- examine you
- ask how you are feeling and whether you have any ongoing treatment side effects
- ask whether you have any new symptoms.
You may also have other tests such as MRI scans or CT scans to check how well treatment has worked. Your doctor and specialist nurse will explain more about this.
If you notice any new symptoms between check-ups, tell your GP, cancer doctor or nurse straight away. Your doctor will check what may be causing your symptoms and whether your symptoms are late effects of treatment.
We have more information about follow-up care after treatment.
Support after anal cancer
People often have many different feelings when they finish anal cancer treatment. You may feel relieved that treatment has finished, but worried about what will happen in the future.
We have information below about some of the things people ask about after anal cancer treatment. But you may have other questions or need information about something else.
Macmillan is here to support you. If you would like to talk, you can:
- call the Macmillan Support Line for free on 0808 808 00 00
- chat to our specialists online
- visit our anal cancer forum to talk to people who have been affected by anal cancer, share your experience, and ask an expert your questions.
Sex life
Anal cancer and its treatment can affect your sex life.
Many people find it difficult to talk about this because they feel embarrassed or self-conscious. Your doctor or nurse will be used to talking about these issues. So it can help to talk to them if you are having problems with your sex life.
Changes may get better over time, but sometimes they are permanent. If you have any problems or are worried about this, talk to your doctor or nurse.
We have more information about how anal cancer treatment can affect your sex life in our information on sex life after bowel cancer.
Body image
Fertility
Some cancer treatments can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.
Other organisations who offer information and support about anal cancer include:
Well-being and recovery
It can take time to recover after anal cancer treatment. Some days you may feel better than others.
Looking after yourself can help speed up your recovery. Even small changes may improve your well-being and long-term health.
Even if you already have a healthy lifestyle, you may choose to make some positive changes after treatment. We have more information on leading a healthy lifestyle after treatment.
It is important to know where to get support or information if you need it. People often need support even some time after anal cancer treatment. But sometimes it is difficult to know who to ask for help.
- ask your GP or someone from your cancer team for advice about support in your area
- search cancercaremap.org to find cancer support services near you
- call us free on 0808 808 00 00 or talk to us talk to us online - our cancer information and support specialists can offer guidance and help you find what you need.
About our information
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.
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References
Below is a sample of the sources used in our anal cancer information. If you would like more information about the sources we use, please contact us at informationproductionteam@macmillan.org.uk
S Rao, MG Guren, K Khan et al. Anal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. 2021. European Society of Medical Oncology. Available from: www.esmo.org/guidelines/guidelines-by-topic/esmo-clinical-practice-guidelines-gastrointestinal-cancers/anal-cancer [accessed January 2023].
O Dahl, MP Myklebust, JE Dale et al. Evaluation of the stage classification of anal cancer by the TNM 8th version versus the TNM 7th version. 2020. Acta Oncologica, 59(9), 1016–1023. Available from: www.tandfonline.com/doi/full/10.1080/0284186X.2020.1778180 [accessed December 2022].
Dr Paul Ross
Reviewer
Consultant Medical Oncologist
Guy's and St Thomas' NHS Foundation Trust
Date reviewed
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