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Colon Cancer Treatment (PDQ®)
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General Information About Colon Cancer
Key Points:
Colon cancer is a disease in which malignant (cancer) cells
form in the tissues of the colon.
The colon is part of the
body’s digestive system. The
digestive system removes and processes nutrients (vitamins, minerals,
carbohydrates, fats, proteins, and water) from foods and helps pass waste
material out of the body. The digestive system is made up of the
esophagus,
stomach, and the
small and large
intestines. The first 6 feet of the
large intestine are called the large bowel or colon. The last 6 inches are the
rectum and the anal canal. The anal
canal ends at the anus (the opening
of the large intestine to the outside of the body).
Gastrointestinal (digestive) system anatomy; shows esophagus, liver, stomach, colon, small intestine, rectum, and anus
Age and health history can affect the risk of developing colon
cancer.
Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors include the following:
Possible signs of colon cancer include a change in bowel habits
or blood in the stool.
These and other symptoms may be caused by colon cancer. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems
occur:
- A change in bowel
habits.
-
Blood (either bright red or very dark) in the
stool.
-
Diarrhea, constipation, or feeling that the bowel does not
empty completely.
- Stools that are narrower than usual.
- Frequent gas pains, bloating,
fullness, or cramps.
- Weight loss for no known reason.
- Feeling very tired.
-
Vomiting.
Tests that examine the rectum, rectal tissue, and blood are
used to detect (find) and diagnose colon cancer.
The following tests and procedures may be used:
-
Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
-
Fecal occult
blood test: A test to check stool (solid waste) for blood that can only be seen with a microscope. Small samples of stool are placed on special cards and returned to the doctor or laboratory for testing.
Fecal Occult Blood Test (FOBT) kit; shows card, applicator, and return envelope.
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Digital rectal
exam: An exam of the rectum. The doctor or nurse inserts a lubricated, gloved finger into the rectum to feel for lumps or anything else that seems unusual.
-
Barium
enema: A series of x-rays of the lower gastrointestinal tract. A liquid that contains barium (a silver-white metallic compound) is put into the rectum. The barium coats the lower gastrointestinal tract and x-rays are taken. This procedure is also called a lower GI series.
Barium enema procedure; shows barium liquid being put into the rectum and flowing through the colon. Inset shows person on table having a barium enema.
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Sigmoidoscopy: A procedure to look inside the rectum and sigmoid (lower) colon for polyps, abnormal areas, or cancer. A sigmoidoscope is inserted through the rectum into the sigmoid colon. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
Sigmoidoscopy; shows sigmoidoscope inserted through the anus and rectum and into the sigmoid colon. Inset shows patient on table having a sigmoidoscopy.
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Colonoscopy: A procedure to look inside the rectum and colon for polyps, abnormal areas, or cancer. A colonoscope is inserted through the rectum into the colon. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
Colonoscopy; shows colonoscope inserted through the anus and rectum and into the colon. Inset shows patient on table having a colonoscopy.
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Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.
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Virtual colonoscopy: A procedure that uses a series of x-rays called computed tomography to make a series of pictures of the
colon. A computer puts the pictures together to create detailed images that may
show polyps and anything else that seems unusual on the inside surface of the colon. This test is also called colonography or CT colonography.
Certain factors affect prognosis
(chance of recovery) and treatment options.
The prognosis
(chance of recovery) depends on the following:
- The
stage of the cancer (whether the
cancer is in the inner lining of the colon only, involves the whole colon, or has spread to other
places in the body).
- Whether the cancer has blocked or created a hole in the colon.
- The blood levels of carcinoembryonic antigen (CEA; a substance in the blood that may be increased when cancer is present) before treatment begins.
- Whether the cancer has recurred.
- The patient’s general health.
Treatment options depend on the following:
- The stage of the cancer.
- Whether the cancer has recurred.
- The patient’s general health.
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Stages of Colon Cancer
Key Points:
After colon cancer has been diagnosed, tests are done
to find out if cancer cells have spread within the colon or to other parts of
the body.
The process used to find out if cancer has spread within the
colon or to other parts of the body
is called staging. The information gathered from the staging process determines the stage of the disease. It is important
to know the stage in
order to plan treatment. The following tests and procedures may be used in the staging process:
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CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
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Lymph node biopsy: The removal of all or part of a lymph node. A pathologist views the tissue under a microscope to look for cancer cells.
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Complete blood
count (CBC): A procedure in which a sample of blood is drawn and
checked for the following:
-
Carcinoembryonic antigen (CEA) assay: A test that measures the level of CEA in the blood. CEA is released into the bloodstream from both cancer cells and normal cells. When found in higher than normal amounts, it can be a sign of colon cancer or other conditions.
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MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the colon. A substance called gadolinium is injected into the patient through a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).
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Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
-
Surgery: A procedure to remove the tumor and see how far it has spread through the colon.
The following stages are used for colon cancer:
Colon cancer staging; shows tumors growing through layers of the colon wall for Stage 0, Stage I, Stage II, Stage III, and Stage IV colon cancer. Inset shows serosa, muscle, submucosa and mucosa layers of the colon wall, and lymph nodes and blood vessels.
Stage 0 (Carcinoma in Situ)
In stage 0, abnormal cells are found in the innermost lining of the
colon. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma
in situ.
Stage I
In stage I, cancer
has formed and spread beyond the innermost tissue layer of the colon wall to the middle layers. Stage I colon cancer is sometimes
called Dukes A colon cancer.
Stage II
Stage II colon cancer is divided into stage IIA and stage IIB.
Stage II colon cancer is sometimes called Dukes B colon cancer.
Stage III
Stage III colon cancer is divided into stage IIIA, stage IIIB, and stage IIIC.
Stage III colon cancer is sometimes called Dukes C colon cancer.
Stage IV
In stage IV, cancer
may have spread to nearby lymph nodes and has spread to other parts of the body, such as the liver or lungs. Stage IV
colon cancer is sometimes called Dukes D colon cancer.
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Recurrent Colon Cancer
Recurrent colon cancer is
cancer that has recurred (come back) after it has been treated. The
cancer may come back in the colon or in other parts of the body, such as the liver,
lungs, or both.
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Treatment Option Overview
Key Points:
There are different types of treatment for patients with colon
cancer.
Different types of treatment are available for patients with colon
cancer. Some treatments are standard (the currently used treatment), and some
are being tested in clinical trials.
Before starting treatment, patients may want to think about taking part in a
clinical trial. A treatment clinical trial is a research study meant to help
improve current treatments or obtain information on new treatments for patients
with cancer. When clinical trials show that a new treatment is better than the
standard treatment, the new
treatment may become the standard treatment.
Clinical trials are taking place in many parts of the country.
Information about ongoing clinical trials is available from the
NCI Web site. Choosing the most appropriate cancer treatment is a
decision that ideally involves the patient, family, and health care
team.
Three types of standard treatment are used. These include the
following:
Surgery
Surgery (removing the cancer
in an operation) is the most common treatment for all
stages of colon cancer. A doctor may
remove the cancer using one of the following types of surgery:
-
Local excision: If the
cancer is found at a very early stage, the doctor may remove it without cutting
through the abdominal wall. Instead,
the doctor may put a tube through the rectum into the colon and cut the cancer out. This
is called a local excision. If the cancer is found in a
polyp (a small bulging piece of
tissue), the operation is called a
polypectomy.
-
Resection: If the cancer is
larger, the doctor will perform a partial colectomy (removing the cancer and a small amount
of healthy tissue around it). The
doctor may then perform an anastomosis (sewing the healthy parts of the colon
together). The doctor will also usually remove lymph nodes near the colon and examine them under
a microscope to see whether they contain cancer.
Three panel drawing showing colon cancer surgery with anastomosis; first panel shows area of colon with cancer, middle panel shows cancer and nearby tissue removed, last panel shows cut ends of colon joined.
- Resection and colostomy: If the doctor is not
able to sew the 2 ends of the colon back together, a
stoma (an opening) is made on the
outside of the body for waste to pass through. This procedure is called a
colostomy. A bag is placed around the stoma to collect the waste. Sometimes the colostomy is
needed only until the lower colon has healed, and then it can be reversed. If
the doctor needs to remove the entire lower colon, however, the colostomy may
be permanent.
Three panel drawing showing colon cancer surgery with colostomy; first panel shows area of colon with cancer, middle panel shows cancer and nearby tissue removed and stoma created, last panel shows a colostomy bag attached to the stoma.
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Radiofrequency ablation: The use of a special probe with tiny electrodes that kill cancer cells. Sometimes the probe is inserted directly through the skin and only local anesthesia is needed. In other cases, the probe is inserted through an incision in the abdomen. This is done in the hospital with general anesthesia.
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Cryosurgery: A treatment that uses an instrument to freeze and destroy abnormal tissue, such as carcinoma in situ. This type of treatment is also called cryotherapy.
Even if the doctor removes all the cancer that can be seen at the
time of the operation, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells
that are left. Treatment given after the surgery, to increase the chances of a
cure, is called adjuvant
therapy.
Chemotherapy
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy).
Chemoembolization of the hepatic artery may be used to treat cancer that has spread to the liver. This involves blocking the hepatic artery (the main artery that supplies blood to the liver) and injecting anticancer drugs between the blockage and the liver. The liver’s arteries then deliver the drugs throughout the liver. Only a small amount of the drug reaches other parts of the body. The blockage may be temporary or permanent, depending on what is used to block the artery. The liver continues to receive some blood from the hepatic portal vein, which carries blood from the stomach and intestine.
The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Radiation therapy
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
New types of treatment are being tested in clinical trials.
These include the following:
Biologic therapy
Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.
This summary section refers to specific treatments under study in
clinical trials, but it may not mention every new treatment being studied.
Information about ongoing clinical trials is available from the
NCI Web site.
Follow-up exams may help find recurrent colon cancer earlier.
After treatment, a blood test to measure
carcinoembryonic antigen (CEA; a
substance in the blood that may be increased when colon cancer is present) may
be done along with other tests to see if the cancer has come back.
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Treatment Options for Colon Cancer
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Stage 0 (Carcinoma in Situ)
Treatment of stage 0 (carcinoma in
situ) may include the following types of
surgery:
Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage 0 colon cancer.
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Stage I Colon Cancer
Treatment of stage I colon
cancer is usually resection/anastomosis.
Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage I colon cancer.
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Stage II Colon Cancer
Treatment of stage II colon
cancer may include the following:
This summary section refers to specific treatments under study in
clinical trials, but it may not mention every new treatment being studied.
Information about ongoing clinical trials is available from the
NCI Web site.
Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage II colon cancer.
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Stage III Colon Cancer
Treatment of stage III colon
cancer may include the following:
This summary section refers to specific treatments under study in
clinical trials, but it may not mention every new treatment being studied.
Information about ongoing clinical trials is available from the
NCI Web site.
Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage III colon cancer.
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Stage IV and Recurrent Colon Cancer
Treatment of stage IV and recurrent colon
cancer may include the following:
Treatment of locally recurrent colon cancer may be local excision.
Special treatments of cancer that has spread to or recurred in the liver may include the following:
Patients whose colon cancer spreads or recurs after initial treatment with chemotherapy may be offered further chemotherapy with a different drug or combination of drugs.
This summary section refers to specific treatments under study in
clinical trials, but it may not mention every new treatment being studied.
Information about ongoing clinical trials is available from the
NCI Web site.
Check for clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with stage IV colon cancer and recurrent colon cancer.
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Changes to This Summary (08/10/2007)
The PDQ cancer information summaries are reviewed regularly and updated as
new information becomes available. This section describes the latest
changes made to this summary as of the date above.
Changes were made to this summary to match those made to the health professional version.
This information is provided from the PDQ® database in collaboration with the NCI.
