Colorectal Cancer

Colorectal Cancer

Topic Overview

Is this topic for you?

This topic will tell you
about the early testing, diagnosis, and treatment of colorectal
cancer. If you want to learn about colorectal cancer that has
come back or has spread, see the topic
Colorectal Cancer, Metastatic or Recurrent.
If you want to learn about anal cancer, see the topic Anal Cancer.

What is colorectal cancer?

Colorectal cancer
means that cells that aren't normal are growing in your
colon or rectum. These cells grow together and form polyps. Over time, some polyps can turn into cancer.

cancer is also called colon cancer or rectal cancer, depending on where the cancer is. It is the third most
common cancer in the United States. And it occurs most often in people older
than 50.

What causes colorectal cancer?

The exact cause of
colorectal cancer is not known. Most cases begin as
small growths, or polyps, inside the colon or rectum.

Colon polyps are very common. If they are
found early, usually through routine screening tests, they can be removed
before they turn into cancer.

What are the symptoms?

Colorectal cancer usually
doesn't cause symptoms until after it has started to spread. See your doctor if
you have any of these symptoms:

  • Pain in your belly
  • Blood in your
    stool or very dark stools
  • A change in your bowel habits, such as
    more frequent stools or a feeling that your bowels are not emptying

How is colorectal cancer diagnosed?

If your doctor
thinks that you may have this cancer, you will need a test, called a
colonoscopy (say "koh-luh-NAW-skuh-pee"), that lets the doctor see the inside of
your entire colon and rectum. During this test, your doctor will remove polyps
or take tissue samples from any areas that don't look normal. The tissue will
be looked at under a microscope to see if it contains cancer.

Sometimes another test, such as a
sigmoidoscopy (say "sig-moy-DAW-skuh-pee"), is used to diagnose colorectal

How is it treated?

Colorectal cancer is usually treated with surgery, chemotherapy, or radiation.

How can you screen for colorectal cancer?

Screening tests can find or prevent many cases of colon and rectal cancer. They
look for a certain disease or condition before any symptoms appear. Experts
recommend routine colorectal cancer testing for everyone age 50 and older who has a
normal risk for colorectal cancer. Your doctor may recommend getting tested more often or at a younger age if you have a higher risk. Talk to your doctor about when you should be tested.

Screening tests include stool tests that can be done at home and procedures, such as colonoscopy, that are done at your doctor's office or clinic.

Frequently Asked Questions

Learning about colorectal cancer:

Being diagnosed:

Getting treatment:

Ongoing concerns:

Living with colorectal cancer:

Health Tools

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Most cases begin as
polyps, which are small growths inside the colon or
Colon polyps are very common. Some polyps can turn into cancer. But doctors can't tell ahead of time which polyps will turn
into cancer. This is why people age 50 and older need regular tests to find out if
they have any polyps and then have them removed.

Some people who are
younger than 50 need regular tests if their medical history puts them at
increased risk for colorectal cancer.


Colorectal cancer in its early stages usually doesn't
cause any symptoms. Symptoms occur later, when the cancer may be harder
to treat. The most common symptoms include:

  • Pain in the belly.
  • Blood in your
    stool or very dark stools.
  • A change in your bowel habits. (You may have
    more frequent stools or a feeling that your bowels aren't emptying
  • Constant
    tiredness (fatigue).
  • In rare cases, unexplained weight

What Happens

How cancer grows and spreads

Cancer is the growth of
abnormal cells in the body. These extra cells grow together and form masses,
called tumors. In
colorectal cancer, these growths usually start as
polyps in the
large intestine (colon or rectum).
If colon polyps aren't found and removed, they may turn into

Cancers in the colon or rectum usually grow very slowly.
It takes most of them years to become large enough to cause symptoms. If the
cancer is allowed to grow, over time it will invade and destroy nearby tissues
and then spread farther. Colorectal cancer spreads first to nearby
lymph nodes. From there it may spread to other parts
of the body, usually the liver. It may also spread to the lungs, and less
often, to other organs in the body.

Survival rates

The long-term outcome, or
prognosis, for colorectal cancer depends on how much the cancer has grown and
spread. Experts talk about prognosis in terms of "5-year survival rates." This means the percentage of people who are still alive 5 years
or longer after their cancer was found. It is important to remember that
these are only averages. Everyone's case is different. And these numbers don't
necessarily show what will happen to you. The estimated 5-year survival rate
for colorectal cancer is:footnote 1

  • 90% or more if cancer is found early and
    treated before it has spread
    . This means that 90 or more out of 100 people will still be alive in 5 years if the cancer is found early and treated before it has spread.
  • 71% if the cancer has spread to
    nearby organs and lymph nodes
    . This means that 71 out of 100 people will still be alive in 5 years if the cancer has spread to
    nearby organs and lymph nodes.
  • 14% if the cancer has spread to the
    liver, lungs, or bones
    . This means that 14 out of 100 people will still be alive in 5 years if the cancer has spread to the
    liver, lungs, or other organs in the body.

These numbers are taken from reports that were done from 2007 to 2013, before newer treatments were available. So the actual chances of your survival are likely to be higher than these numbers.

What Increases Your Risk

A risk factor for colorectal cancer is something that increases your chance of getting this cancer. Having one or more of these risk factors can make it more likely that you will get colorectal cancer. But it doesn't mean that you will definitely get it. And many people who get colorectal cancer don't have any of these risk factors.

Risks you can change

There are lifestyle actions you can take to lower some of the risk factors for colorectal cancer. These actions include:

  • Maintain a healthy weight.
  • Be physically active.
  • Eat healthy foods, including vegetables, fruits, and whole grains. Avoid eating a lot of red meat or processed meats.
  • If you smoke, get help to quit.
  • If you drink alcohol, limit how much you drink.

Risks you can't change

Your age

Getting older is a risk factor for colorectal cancer. Experts recommend that people at average risk for colorectal cancer begin screening at age 50, since most cases of colorectal cancer are diagnosed in people older than 50.

Your race and ethnicity

African Americans are at greater risk of getting colorectal cancer (and dying from it) than non-Hispanic whites. And non-Hispanic white people have a higher risk than other major racial or ethnic groups, such as Hispanics, Asians, and Pacific Islanders.footnote 2

Ashkenazi Jews (Jewish people whose ancestors came from Eastern Europe) who have inherited certain genes are also at a higher risk for getting colorectal cancer.footnote 3

Your family's medical history

are more likely to get colorectal cancer if one of your parents, brothers,
sisters, or children has had the disease. Your risk is higher if this family member had colorectal cancer younger than 45 years old, or if more than one family member had the disease.

Some common gene changes increase the chance of colorectal cancer. These changes are
familial adenomatous polyposis (FAP) and
Lynch syndrome, also called hereditary nonpolyposis colorectal cancer (HNPCC). Many
people with these changed genes will get colorectal cancer if they aren't
carefully watched.
Genetic testing can tell you if you carry a
changed, or mutated, gene that can cause FAP or HNPCC.

Your medical history

chances of getting colorectal cancer are higher if you have had:

When To Call a Doctor

Call your doctor if you have any
symptoms of
colorectal cancer, such as:

  • A change in bowel habits.
  • Bleeding
    from your rectum, including bright red or dark blood in your stools or stools
    that look black.
  • Constant or frequent diarrhea, constipation, or a
    feeling that your bowel doesn't empty completely.
  • Stools that are
    narrow (may be as narrow as a pencil).
  • Belly pain or problems
    with gas or bloating.
  • Unexplained weight loss.
  • Constant
    tiredness (fatigue).

Because colorectal cancer often doesn't cause any
symptoms, talk with your doctor about
screening tests. Screening helps doctors find a
certain disease or condition before any symptoms appear.

Who to see

Health professionals who can evaluate your symptoms of
colorectal cancer include:

If your doctor thinks you may have colorectal cancer, he
or she may advise you to see a
general surgeon or a
colorectal surgeon. Colorectal cancer is treated
by surgeons,
medical oncologists, and
radiation oncologists.

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

If your doctor thinks you may have
colorectal cancer, he or she will ask you questions
about your
medical history and give you a physical exam. Other
tests may include:

  • A
    colonoscopy. Your doctor uses a
    lighted scope to view the inside of your entire colon. Polyps can be removed during this test. A colonoscopy is recommended when another screening test shows that you may
    have colorectal cancer.footnote 4
  • A
    sigmoidoscopy. Your doctor uses a
    lighted scope to view the lower part of your intestine. Doctors can also remove polyps during this test.
  • A
    barium enema. A whitish liquid with barium is
    inserted through your rectum into your intestine. The barium outlines the
    inside of the colon so that it can be seen on an X-ray.
  • A
    biopsy. A sample of tissue is taken from the
    inside of your intestine and examined under a microscope. A doctor called a
    pathologist can look at the tissue sample and see if
    it contains cancer.
  • A
    complete blood count, which is a blood test. It is
    used to look into symptoms such as fatigue, weakness, anemia, bruising, or
    weight loss.

For people who have an increased risk for colorectal
cancer, regular
colonoscopy is the recommended screening test. It allows your doctor to remove polyps (polypectomy) and take tissue samples at
the same time.

When you are diagnosed with colorectal cancer,
your doctor may order other tests to find out if the cancer has spread.
These tests include:

Early detection

Routine screening can reduce deaths from colorectal cancer.

Talk to your doctor about which test is right for you.
People with a higher risk for colorectal cancer, such as those with a strong family history of colorectal cancer, may need to start routine
testing before age 50 and have it more often.

Treatment Overview

You and your doctor will work
together to decide what your treatment should be. You will consider your own
preferences and your general health. But the stage of your cancer is the most important tool for
choosing your treatment. Staging is a way for your doctor to tell how far, if at all,
your cancer has spread.


Surgery is almost
always used to remove
colorectal cancer. Sometimes a simple operation can be done during a colonoscopy or
sigmoidoscopy to remove small polyps and a small amount of tissue around
them. But in most cases, a major operation is needed to remove the cancer and part of the
colon or rectum around it. If cancer has spread to
another part of your body, such as the liver, you may need more far-reaching


Chemotherapy uses
medicines to destroy cancer cells
throughout the body. Several medicines are often used together.

Radiation therapy

Radiation therapy uses X-rays to destroy cancer cells.
This is used for some types of cancer in the rectum. Radiation therapy
is often combined with surgery or chemotherapy. To learn more, see Other Treatment.

Cancers that have not spread beyond the colon or rectum may
need only surgery. If the cancer has spread, you may need
radiation therapy,
chemotherapy, or both.

Side effects of treatment

Surgery, chemotherapy, and radiation can have serious side effects. But your medical team will help you manage the side effects of your treatment. This may include medicines for pain after surgery or medicines to control nausea and vomiting if you have chemotherapy.

Talk with your doctor and medical team about your side effects. Some side effects, such as pain or tingling in your hands or feet that gets worse (peripheral neuropathy), may be a sign that your medicines need to be changed.

For tips on how to manage side effects at home, see Home Treatment.

Regular checkups

After you have had colorectal
cancer, your chances of having it again go up. It's important to keep seeing your doctor and be tested regularly to help find any returning cancer or
new polyps early. After your treatment, you will
need regular checkups by a
family doctor,
general practitioner,
medical oncologist,
radiation oncologist, or
surgeon, depending on your case.

When cancer comes back or spreads

Colorectal cancer comes back in about half of people who have surgery
to remove the cancer.footnote 5 The cancer may be more likely
to come back after surgery if it was not found in an early stage. Cancer that has spread or comes back is harder to treat, but sometimes treatments are successful. For more information, see
the topic
Colorectal Cancer, Metastatic and Recurrent.

Support and resources

Finding out that you have cancer can change your life. You may feel like your world has turned upside down and you have lost all control. Talking with family, friends, or a counselor can really help. Ask your doctor about support groups. Or call the American Cancer Society (1-800-227-2345) or visit its website at

To learn more about colon and rectal cancer, go to the website of the National Cancer Institute at


Screening for colorectal cancer

Screening tests look for a certain
disease or condition before any symptoms appear. Experts recommend routine
colorectal cancer screening. The U.S. Preventive Services Task Force says:footnote 6

  • People ages 50 to 75 should have a screening test starting at age 50.
  • People ages 76 to 85 can work with their doctors to decide if screening is a good option.
  • People ages 86 and older are advised that screening for colorectal cancer is usually not helpful.

Your doctor may recommend earlier and more frequent testing if you have a higher risk for colorectal cancer. Talk to
your doctor about when you should be tested.

Genetic testing

If you have a
very strong family history of colorectal cancer, you may want to talk to your doctor or a
genetic counselor about having a blood test to look for changed genes.
Genetic testing can tell you if you carry a
changed, or mutated, gene that can cause colorectal cancer. Having certain genes
greatly increases your risk of colorectal cancer. But most cases of colorectal cancer aren't caused by changed genes.

Home Treatment

Managing side effects

During treatment for colorectal cancer, you can do things at home to help manage your side effects and symptoms. If your doctor has given you instructions or medicines to treat these problems, be sure to also use them.

In general, healthy habits such as eating
a balanced diet and getting enough sleep and exercise may help control your

You can try home treatments:

  • For nausea or vomiting, such as ginger tea, peppermint candy or gum, or drinking enough fluids so that you don't get dehydrated.
  • For diarrhea, such as taking small, frequent sips of water and bites of salty crackers.
  • For constipation, such as getting plenty of water and fiber in your diet. Do not use a laxative without first talking to your doctor.

Other problems that can be treated at home include:

  • Sleep problems. If you have trouble sleeping, try having a regular bedtime, getting exercise daily,
    and avoiding
    caffeine late in the day.
  • Feeling very tired. If you lack energy or become weak easily, try to get extra rest and plan your schedule to make the most of the energy you have.
  • Pain. There are many home treatments that can help when you have pain, such as over-the-counter pain relievers, heat packs, or cold packs.
    Talk to your doctor before using any home treatment for
  • Mouth sores. This includes watching what you eat and drink and rinsing regularly with mouthwash or an antacid.

Managing stress from having cancer

Having cancer can be very stressful. Finding new ways of coping with your stress may improve your overall quality of life.

These ideas may help:

  • Take steps to reduce your stress. Find new ways to relax, such as yoga or
    visualization exercises.
  • Get the support you need. Spend time with people who care about you. Let them help you.
  • Talk about your feelings. Try
    meeting with a counselor or joining a support group where you can share your experience.
  • Ask your doctor to help you find other sources
    of support and information.

Your feelings about your body may change after treatment.
Dealing with your body image may involve talking
openly with your partner about your worries and discussing your feelings with a

Having cancer can change your life in many ways. For help with managing these changes, see the topic Getting Support When You Have Cancer.

For more information about learning how to live with cancer, read "Taking Time: Support for People With Cancer" from the National Cancer Institute. This booklet is available online at


Chemotherapy is the use of medicines to control
the cancer's growth or relieve symptoms. Often the medicines are given through a
needle in your vein. Your blood vessels carry the medicines through your body.
Sometimes the medicines are available as pills. And sometimes they are
given as a shot, or injection.

Several medicines are used to
colorectal cancer. There are also several medicines
available for treating side effects.

Medicine choices

A combination of drugs often works better than a single
drug in treating colorectal cancer. The most commonly used drugs are:

  • Fluorouracil (5-FU) combined with
  • Oxaliplatin.
  • Capecitabine.
  • Irinotecan.

Hair loss can be a common side effect with some types of
chemotherapy. But hair loss usually isn't a side effect of these drugs.

Treating the side effects

Your doctor may
prescribe medicines that can help relieve side effects of chemotherapy. These
side effects can include mouth sores, diarrhea, nausea, and vomiting. Your
doctor may prescribe
medicines to control nausea and vomiting.

There also are things you can do at home to manage side
effects. See Home Treatment for more information.

What to think about

radiation may be combined to treat some types of
colorectal cancer. Radiation or chemotherapy given before or after surgery can
destroy microscopic areas of cancer to increase the chances of a cure.


Surgery to remove cancer is almost always the
main treatment for
colorectal cancer. The type of surgery depends on the
size and location of your cancer.

Side effects are common after
surgery. You may be able to reduce the severity of your side effects at home.
See Home Treatment for more information.

Surgery choices

  • Polypectomy. When colorectal cancer is
    discovered in its very early stages, it can be removed during a
    sigmoidoscopy or
    colonoscopy. The surgeon cuts out not just the polyp,
    but also a small amount of tissue around it. The surgeon does not need to cut
    into the abdomen.
  • Bowel resection. This involves cutting out the cancer as well as the sections of the colon or rectum
    that are next to it. Then the two healthy ends of the colon or rectum are sewn
    back together. This surgery is used when the cancer is larger. It can be done in two ways:

    • Open resection. The surgeon makes a long cut (incision) in the belly, completes the bowel resection, and closes the
    • Laparoscopic surgery. This is done with several small incisions in the belly
      for a tiny camera and special tools. But laparoscopic surgery can't always be
      done, such as when the cancer has spread to areas outside the colon.

Your doctor may suggest radiation therapy or chemotherapy if he or she thinks the cancer may come back (recur). If the cancer has spread to nearby lymph nodes, you may need chemotherapy after your surgery. Or if your surgery shows that the cancer has spread outside your colon or rectum, you may need radiation therapy.

What to think about

Sometimes after a bowel resection, the two
ends of the colon or rectum can't be sewn back together. When this happens, a
colostomy is performed. But most people don't need a

Other Treatment

Radiation therapy

Radiation therapy uses X-rays to destroy
colorectal cancer cells and shrink tumors. It is often
used to treat rectal cancer, usually combined with surgery. It is used less
often to treat colon cancer. It may also be combined with

Radiation may be given:

  • Externally, using a machine outside the body
    that points a beam of radiation at the tumor.
  • Internally, by placing tiny radioactive "seeds" next to or into
    the cancer.

Compared to surgery alone, radiation given before surgery
may reduce the risk that rectal cancer will return, and it may help you live
longer.footnote 5

Complementary therapies

People sometimes use complementary therapies along with medical treatment to help relieve symptoms and side effects of cancer treatments. Some of the complementary therapies that may be helpful include:

Mind-body treatments like the ones listed above may help you feel better. They can make it easier to cope with cancer treatments. They also may reduce chronic low back pain, joint pain, headaches, and pain from treatments.

Before you try a complementary therapy, talk to your doctor about the possible value and side effects. Let your doctor know if you are already using any of these therapies. Complementary therapies are not meant to take the place of standard medical treatment. But they may improve your quality of life and help you deal with the stress and side effects of cancer treatment.

Clinical trials

You may be interested in taking part in research studies called clinical trials. Clinical trials are based on the most up-to-date information. They are designed to find better ways to treat people who have cancer. People who don't want standard treatments or aren't cured by standard treatments may want to take part in clinical trials. These are ongoing in most parts of the United States and in some other countries around the world for all stages of colorectal cancer.

Other Places To Get Help


American Cancer Society (ACS)
250 Williams Street NWAtlanta, GA 30303

National Cancer Institute (U.S.) (or for live help online)



  1. National Cancer Institute (2017). SEER cancer stat facts: Colon and rectum cancer. National Cancer Institute. Accessed November 10, 2017.
  2. American Cancer Society (2011). Colorectal Cancer Facts and Figures 2011–2013. Atlanta: American Cancer Society. Available online:
  3. Libutti SK, et al. (2011). Cancer of the colon. In VT DeVita Jr. et al., eds., DeVita, Hellman and Rosenberg's Cancer: Principles and Practice of Oncology, 9th ed., pp. 1084–1126. Philadelphia: Lippincott Williams and Wilkins.
  4. Winawer S, et al. (2003). Colorectal cancer screening and surveillance: Clinical guidelines and rationale—Update based on new evidence. Gastroenterology, 124(2): 544–560.
  5. Lewis C (2007). Colorectal cancer screening, search date November 2006. Online version of BMJ Clinical Evidence:
  6. U.S. Preventive Services Task Force (2016). Screening for colorectal cancer: U.S. Preventive Services Task Force recommendation statement. JAMA, 315(23): 2564–2575. DOI:10.1001/jama.2016.5989. Accessed June 27, 2016.

Other Works Consulted

  • National Cancer Institute (2010). Colon Cancer PDQ: Treatment—Health Professional Version. Available online:
  • National Cancer Institute (2011). Colon Cancer PDQ: Treatment—Patient Version. Available online:
  • National Cancer Institute (2011). Rectal Cancer PDQ: Treatment—Health Professional Version. Available online:
  • National Cancer Institute (2012). Genetics of Colorectal Cancer PDQ—Health Professional Version. Available online:
  • National Cancer Institute (2012). Rectal Cancer Treatment (PDQ)—Patient Version. Available online:
  • National Comprehensive Cancer Network (2012). Rectal cancer. NCCN Clinical Practice Guidelines in Oncology, version 3. Available online:


ByHealthwise StaffPrimary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine Kathleen Romito, MD - Family Medicine Specialist Medical Reviewer Kenneth Bark, MD - General Surgery, Colon and Rectal Surgery Adam Husney, MD - Family Medicine

Current as ofNovember 22, 2017

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