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Getting diagnosed with anal cancer

Tests for anal cancer

The anus is the part of the bowel that opens to the outside of the body. You might have a number of tests to check for anal cancer.

The tests you might have include:

  • an examination of your anus and back passage (rectum)

  • taking a sample of tissue (biopsy) from your anus

  • scans

  • taking a sample of tissue from the in your groin

Tests your GP might do

Most people with symptoms that could be due to cancer start by contacting their GP surgery. Your first appointment may be a telephone appointment. Your GP surgery then might arrange for you to go in and see a doctor or other healthcare professional.

The tests your GP might do include one or more of the following:

  • an examination of your abdomen (tummy), anus and rectum

  • a test that looks for tiny traces of blood in a sample of your poo - a Faecal Immunochemical Test (FIT)

  • blood tests

Your GP may also ask you for another sample of poo to check for inflammation in the bowel. This is to test for a protein called faecal calprotectin. Your GP or practice nurse will give you a sample pot to take away with you. You bring it back once you have collected the poo sample.

Read more about seeing your GP for symptoms of anal cancer

Examination of your abdomen, anus and rectum

Your doctor may ask if they can feel your tummy. This is to check for any areas that might be swollen or might not feel normal, including a lump. Tell your doctor if you have pain anywhere, and they can feel those areas too.

They also ask to feel the inside of your anus and rectum using their gloved finger. This is called a digital rectal exam (DRE). They look for any lumps or hard areas.

It’s normal to feel anxious about having an examination but it usually only takes a few minutes. Your doctor will usually ask if you want someone else in the room to act as a chaperone. This is usually a health professional such as a practice nurse.

Ask your doctor if you would also like a friend or relative with you.

Find out more about having an examination of your anus and rectum

Testing for blood in your poo using FIT

FIT is a test that looks for blood in a sample of your poo. It looks for tiny traces of blood that you might not be able to see which could be a sign of cancer.

Not everyone has this test. For example, your GP might refer you to a specialist doctor without doing a FIT if your anus has either:

  • a lump

  • an abnormal looking wound (ulcer)

Read more about FIT and how you do the test

Blood tests

Blood tests can check your general health. This includes how well your liver and kidneys are working. Your doctor can also check the number of  such as red blood cells. 

Find out more about blood tests

Tests your specialist might do

Depending on the results of your tests, your GP might refer you to a specialist. You are usually referred to a lower gastrointestinal (lower GI) clinic. At the clinic you may see a specialist nurse or colorectal doctor. They specialise in bowel, rectum and anal problems, including cancer.

Your specialist usually does an anal examination. They use a thin tube to look at the anus (anoscopy) and take a biopsy. 

If the biopsy contains cancer cells, you usually have other tests. These may include:

  • an MRI scan

  • a CT scan

  • a PET-CT scan

  • taking a sample of tissue from the lymph nodes in your groin

Anal examination (anoscopy) and biopsy

Your specialist looks at your anus and the area around it using a thin tube called an anoscope. They might also look at your rectum using a slightly longer tube. This is called a proctoscopy.

If your specialist finds any abnormal areas they take a biopsy and send it to a doctor called a pathologist. The pathologist look at the biopsy under a microscope to see if it contains cancer cells.

You usually have this test in the outpatient department using a . You may also have it in the operating theatre under a  but this is rare.

Read more about having an anal examination and biopsy

MRI scan

MRI stands for magnetic resonance imaging. It uses magnetism and radio waves to take pictures of the inside of the body.

You might have an MRI scan of your pelvis. This is the area between your hip bones. Doctors use the MRI scan to find out:

  • where in the anus the cancer is

  • how big it is and whether it has spread anywhere else in your pelvis (the stage)

  • check how well the treatment is working

You may have an injection of a dye (contrast medium) before the scan. This makes the pictures easier to see.

Find out more about having an MRI scan

CT scan

CT (or CAT) stands for computed (axial) tomography. It is a test that uses x-rays and a computer to create detailed pictures of the inside of your body.

You may have a CT scan of your chest, tummy (abdomen) and pelvis. This is to find out whether the cancer has spread to other parts of the body.

You may have an injection of contrast medium before the scan.

Read more about having a CT scan

PET-CT scan

A PET-CT scan combines a CT scan and a . This type of scan can give detailed information about the cancer.

You might have a PET-CT scan to:

  • help decide the best treatment for you

  • show how well treatment is working

  • check whether the cancer has come back

Find out more about having a PET-CT scan

Checking for cancer cells in the lymph nodes in your groin

Anal cancer can sometimes spread into the lymph nodes in your groin. To check for this, you may have an ultrasound of the groin area.

The ultrasound scanner has a microphone that gives off sound waves. The sound waves bounce off the organs inside your body, and the microphone picks them up. The microphone links to a computer that turns the sound waves into a picture on the screen.

If a lymph nodes look abnormal, your doctor can use the ultrasound to guide a needle into it. They can then take a small sample of cells. This is called a fine needle aspiration (FNA).

Find out about having a lymph node ultrasound and biopsy

Other tests

Occasionally your doctor may want you to have other tests. This depends on your general health, symptoms and the cancer. Your doctor will explain what the tests are for and how to prepare for them.

Find out about other tests and scans from our A to Z list

Treatment

These tests help your doctor find out if you have anal cancer. If you do, the tests help your doctor find out the size and if it has spread. This is called the cancer stage.

Read about the stages of anal cancer

Knowing the cancer stage is important. This is because doctors recommend your treatment according to the stage.

Find out about the treatment options for anal cancer

Coping with anal cancer

Coping with a diagnosis of anal cancer can be difficult. There is help and support available to you and your family.

Read more about coping with anal cancer

Last reviewed: 22 Apr 2025

Next review due: 22 Apr 2028

What is anal cancer?

Anal cancer is when abnormal cells in the anus divide in an uncontrolled way. It can start in different parts of the anus and different types of cell.

Symptoms of anal cancer

Anal cancer symptoms may include bleeding, bowel changes and severe itching around the anus (pruritus). It is important to see your doctor if you have any of these symptoms.

Tests and scans A to Z

Find out about tests to diagnose cancer and monitor it during and after treatment, including what each test can show, how you have it and how to prepare.

Treatment for anal cancer

Treatments include radiotherapy with chemotherapy (chemoradiotherapy) and surgery. For advanced cancer you might have chemotherapy or radiotherapy on their own.

Coping with anal cancer

Coping with anal cancer can be difficult. You might find it helpful to speak about your feelings and there are people who can support you and your family.

Anal cancer main page

Anal cancer is cancer that starts in the anus. The anus is also called the anal canal.

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