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If You Have Anal Cancer

What is anal cancer?

Cancer that starts in the anus is called anal cancer. It starts when cells in the anus grow out of control and crowd out normal cells.

Cancer cells can spread to other parts of the body. Cancer cells in the anus can sometimes travel to the liver and grow there. When cancer cells do this, it’s called metastasis. To doctors, the cancer cells in the new place look just like the ones from the anus.

Cancer is always named for the place where it starts. So when anus cancer spreads to the liver (or any other place), it’s still called anal cancer. It’s not called liver cancer unless it starts from cells in the liver.

diagram showing anal structure including the anal canal, rectum, blood vessels, sphincter muscles, mucosa and anal margin

Ask your doctor to use this picture to show you where the cancer is.

The anus

The anus is the end of the digestive tract – the channel that food moves through as it’s used by the body. Solid waste (poop) comes out of the anus.

Are there different kinds of anal cancer?

There are many types of anal cancer. Most are rare. Your doctor can tell you more about the type you have.

The most common type is called squamous cell cancer. This type of tumor starts in the cells that line the inside of the anus and have grown into the deeper layers of the anus.

Anal cancer is also often put into 2 groups depending on where it starts in the anus - the anal canal or the perianal area. They are sometimes treated differently.

Questions to ask the doctor

  • Why do you think I have anal cancer?
  • Is there a chance I don’t have cancer?
  • Would you please write down the kind of cancer you think I might have?
  • What will happen next?

How does the doctor know I have anal cancer?

Some anal cancers cause no symptoms at all. But symptoms of anal cancer can include changes in your poop, bleeding, itching, and pain or a lump at the anal opening. The doctor will ask you questions about your health and do a physical exam. The doctor will also look at your anus and may put a gloved finger inside to check for lumps. (This is called a rectal exam. The rectum is the part of the large intestine that connects to the anus.)

If signs are pointing to anal cancer, more tests will be done. Here are some of the tests you may need:

Anoscopy: For this test, a hollow firm tube about 3 to 4 inches long (called an anoscope) is covered with a gel and gently put into the anus. A light at the end of this tube lets the doctor see the inside of the lower rectum and anus. A sample of tissue (a biopsy) can be taken and then tested in the lab. You will be awake for this test, but it should not hurt.

Endoscopy: For this test, a flexible (not firm) tube with a tiny video camera and light on the end (called an endoscope) is put into the anus, rectum, and sometimes the entire colon to look inside. This flexible tube is much longer than the anoscope and might be used to make sure that an anal cancer symptom, such as bleeding, is not coming from another area like the rectum or colon. It can also be used to take out cells (a biopsy) from inside these areas. You will be given medicine to stay drowsy or asleep during this test.

Ultrasound: For this test, a small thin probe is put into the anus and rectum. This can be uncomfortable, but should not hurt. The probe gives off sound waves to make pictures of the inside of the body. This test can be used to see how deep the cancer has grown into the tissues around the anus.

CT scan or CAT scan: A CT scan is like an x-ray, but the pictures of your insides are more detailed. CT scans can also be used to help do a biopsy and can show if the cancer has spread.

MRI scan: This test uses radio waves and strong magnets instead of x-rays to make detailed pictures. This test may be used to check the nearby lymph nodes or the liver for cancer spread.

Chest x-ray: X-rays may be done to see if the cancer has spread to the lungs.

PET scan: PET scans use a special kind of sugar that can be seen inside your body with a special camera. If there is a cancer, this sugar shows up as “hot spots” where the cancer is found. This test can help show if the cancer has spread. Sometimes, a PET scan is done with a CT scan to see areas of cancer better.  

Anal biopsy

In a biopsy, the doctor takes out a small piece of tissue where the cancer seems to be. The tissue is checked for cancer cells. A biopsy is the only way to know for sure if you have cancer. For anal cancer, a biopsy is most often done during an endoscopy. If the tumor is very small and is only on the lining of the anus, the doctor may be able to take out all of the tumor during the biopsy.

There are many types of biopsies. Ask your doctor what kind you will need. Each type has reasons for and against doing them. The choice of which type to use depends on your own case.

Questions to ask the doctor

  • What tests will I need to have?
  • Who will do these tests?
  • Where will they be done?
  • Who can explain them to me?
  • How and when will I get the results?
  • Who will explain the results to me?
  • What do I need to do next?

How serious is my cancer?

If you have anal cancer, the doctor will want to find out how far it has spread. This is called staging. Your doctor will want to find out the stage of your cancer to help decide what type of treatment is best for you.

The stage describes the growth or spread of the cancer through the anus. It also tells if the cancer has spread to nearby organs or to organs farther away.

Your cancer can be stage 1, 2, 3, or 4. The lower the number, the less the cancer has spread. A higher number, like stage 4, means a more serious cancer that has spread beyond the anus. Be sure to ask the doctor about the cancer stage and what it means.

Questions to ask the doctor

  • Do you know the stage of the cancer?
  • If not, how and when will you find out the stage of the cancer?
  • Would you explain to me what the stage means in my case?
  • Based on the stage of the cancer, how long do you think I’ll live?
  • What will happen next?

What kind of treatment will I need?

There are many ways to treat anal cancer, including surgery, radiation, chemotherapy, and immunotherapy.

Surgery and radiation are used to treat only the cancer. They do not affect the rest of the body. Chemo drugs and immunotherapy go through the whole body. They can reach cancer cells almost anywhere in the body. The treatment plan that’s best for you will depend on:

  • The stage of the cancer and where it started in the anus (anal canal or perianal area)
  • The chance that a type of treatment will help
  • Your age
  • Other health problems you have
  • Your feelings about the treatment and the side effects that might come with it

Surgery for anal cancer

Most people with anal cancer do not need surgery. If surgery is needed, the kind of surgery depends on the type of tumor and where it is.

Local resection

A local resection may be done if the cancer is small and has not spread. Only the tumor and a small rim of tissue around it are taken out. In most cases, the muscle that opens and closes the anus is not damaged. If so, you’ll be able to control your poop and have it come out the anus.

Abdominoperineal resection (APR)

Abdominoperineal resection is not used a lot, but it may be an option if other treatments don’t get rid of the cancer.

For this surgery, the doctor makes 2 cuts: 1 through the belly and 1 around the anus. Then the anus and part of the rectum are taken out, and sometimes nearby lymph nodes are taken out, too. After an APR you’ll have an opening on your lower belly where poop will come out. (This is called a colostomy.)

Side effects of surgery

Any type of surgery can have risks and side effects. Be sure to ask the doctor what you can expect. Ask how you will poop after surgery. If you have problems, let your doctors know. They should be able to help you with any problems you might have.

Radiation treatments

Radiation uses high-energy rays (like x-rays) to kill cancer cells. In anal cancer, it’s most often given along with chemotherapy. Radiation can also be used to relieve symptoms such as pain, bleeding or other problems that happen when the anal cancer has grown very large or has spread to other areas like the bones. It’s often given in small doses every day for many weeks.

There are 2 main ways radiation can be given. It's most often aimed at the anus from a machine outside the body. This is called external beam radiation. In some cases, a tube of radioactive seeds might be put right into the anus near the cancer. This is called brachytherapy.

Side effects of radiation treatments

If your doctor suggests radiation treatment, ask about what side effects might happen. The most common side effects of radiation are:

  • Skin changes where the radiation is given
  • Feeling very tired (fatigue)
  • Bowel movements may hurt
  • Nausea
  • Diarrhea
  • In women, radiation can irritate the vagina. This may hurt and can cause vaginal discharge.

Most side effects get better after treatment ends and many can be treated. Some might last longer. Talk to your cancer care team about what you can expect.


Chemo is the short word for chemotherapy – the use of drugs to fight cancer. The drugs may be given into a vein or taken as pills. These drugs go into the blood and spread through the body.

Chemo is given in cycles or rounds. Each round of treatment is followed by a break to give the body time to recover. Most of the time, 2 or more chemo drugs are given. Treatment often lasts for many months.

Chemo given along with radiation therapy is often the first treatment for most anal cancers. This is called chemoradiation. It may cure the cancer without surgery.

Side effects of chemo

Chemo might make you feel very tired, sick to your stomach, and cause your hair to fall out. But these problems go away after treatment ends.

There are ways to treat most chemo side effects. If you have side effects, talk to your cancer care team so they can help.


Immunotherapy is treatment that boosts your own immune system to attack the anal cancer cells. These drugs may be given into a vein.

Side effects of immunotherapy

Immunotherapy can cause different side effects depending on which drug is used. These drugs may make you feel tired, sick to your stomach, or cause a rash. Most of these problems go away after treatment ends.

There are ways to treat most of the side effects caused by immunotherapy. If you have side effects, talk to your cancer care team so they can help.

Clinical trials

Clinical trials are research studies that test new drugs or other treatments in people. They compare standard treatments with others that may be better.

Clinical trials are one way to get the newest cancer treatment. They are the best way for doctors to find better ways to treat cancer. If your doctor can find one that’s studying the kind of cancer you have, it’s up to you whether to take part. And if you do sign up for a clinical trial, you can always stop at any time.

If you would like to learn more about clinical trials that might be right for you, start by asking your doctor if your clinic or hospital conducts clinical trials. See Clinical Trials to learn more.

What about other treatments that I hear about?

When you have cancer you might hear about other ways to treat the cancer or treat your symptoms. These may not always be standard medical treatments. These treatments may be vitamins, herbs, special diets, and other things. You may wonder about these treatments.

Some of these are known to help, but many have not been tested. Some have been shown not to help. A few have even been found to be harmful. Talk to your doctor about anything you’re thinking about using, whether it’s a vitamin, a diet, or anything else.

Questions to ask the doctor

  • What treatment do you think is best for me?
  • What’s the goal of this treatment? Do you think it could cure the cancer?
  • Will treatment include surgery? If so, who will do the surgery?
  • What will the surgery be like? How will I poop after surgery?
  • What’s the goal of these treatments?
  • What side effects could I have from these treatments?
  • What can I do about side effects that I might have?
  • Is there a clinical trial that might be right for me?
  • What about special vitamins or diets that friends tell me about? How will I know if they are safe?
  • How soon do I need to start treatment?
  • What should I do to be ready for treatment?
  • Is there anything I can do to help the treatment work better?
  • What’s the next step?

If you need more information about possible side effects of treatment, visit Managing Cancer-related Side Effects.

What will happen after treatment?

You’ll be glad when treatment is over. For years after treatment ends, you will still need to see your cancer doctor. Be sure to go to all of these follow-up visits. You will have exams, blood tests, and maybe other tests to see if the cancer has come back.

Follow-up doctor visits after treatment may be needed as often as every 3 to 6 months for at least 3 years. They will be less often after 3 years or so. During these visits, your doctor will ask about any symptoms you’re having and will do a physical exam. Blood tests, rectal exams, anoscopy, and imaging tests (like CT scans) might be done.

Having cancer and dealing with treatment can be hard, but it can also be a time to look at your life in new ways. You might be thinking about how to improve your health. Call us at 1-800-227-2345 or talk to your cancer care team to find out what you can do to feel better.

You can’t change the fact that you have cancer. What you can change is how you live the rest of your life – making healthy choices and feeling as good as you can.

For connecting and sharing during a cancer journey

Anyone with cancer, their caregivers, families, and friends, can benefit from help and support. The American Cancer Society offers the Cancer Survivors Network (CSN), a safe place to connect with others who share similar interests and experiences. We also partner with CaringBridge, a free online tool that helps people dealing with illnesses like cancer stay in touch with their friends, family members, and support network by creating their own personal page where they share their journey and health updates.   

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

Adenocarcinoma (AD-no-KAR-suh-NO-muh or AD-uh-no-KAR-suh-NO-muh): Cancer that starts in the gland cells that line certain organs and make and release substances into the body, such as mucus, digestive juices, or other fluids.

Abdominoperineal resection (ab-DAH-muh-no-PAIR-uh-NEE-uhl re-SEK-shun): Often shortened to AP resection or APR. This is surgery to take out the anus, rectum, and part of the colon (large intestine). A permanent colostomy is needed after this surgery. See colostomy.

Biopsy (BY-op-see): Taking out a small piece of tissue to see if there are cancer cells in it.

Carcinoma (CAR-sin-O-muh): Cancer that starts in the lining layer of organs. Most cancers are carcinomas.

Colostomy (kuh-LAHS-tuh-me): An opening made in the skin on the belly to make a new path to get rid of poop or stool. A small pouch is used to cover the opening to collect the poop.

Endoscopy (en-DOS-koh-pee): The use of a tube with a lens or tiny video camera on the end (called a scope) to look inside the body. Can be used to do a biopsy. See biopsy.

Lymph nodes (limf nodes): Small, bean-shaped sacs of immune system tissue found all over the body and connected by lymph vessels; also called lymph glands.

Metastasis (muh-TAS-tuh-sis): Cancer cells that have spread from where they started to other places in the body.


We have a lot more information for you. You can find it online at Or, you can call our toll-free number at 1-800-227-2345 to talk to one of our cancer information specialists.

Last Revised: September 9, 2020

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