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
lymph nodes 
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:
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an examination of your abdomen (tummy), anus and rectum
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a test that looks for tiny traces of blood in a sample of your poo - a Faecal Immunochemical Test (FIT)
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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.
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.
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)
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.
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:
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an MRI scan
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a CT scan
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a PET-CT scan
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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.
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:
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where in the anus the cancer is
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how big it is and whether it has spread anywhere else in your pelvis (the stage)
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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.
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.
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:
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help decide the best treatment for you
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show how well treatment is working
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check whether the cancer has come back
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).
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.
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.
Knowing the cancer stage is important. This is because doctors recommend your treatment according to the stage.
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.
