Most cancers are named after the part of the body where the cancer first starts. Colorectal cancer begins in either the colon or the rectum. Both are part of the digestive tract, also called the GI (gastrointestinal) tract. This is where food is processed to create energy and rid the body of waste matter.

After food is chewed and swallowed, it travels down the esophagus to the stomach. There it is partly broken down and sent to the small intestine. The small intestine continues breaking down the food and absorbs most of the nutrients. It is the longest section of the GI tract. The small intestine joins the large intestine or large bowel, a muscular tube about five feet long. The first part of the large bowel, called the colon continues to absorb water and nutrients from the food and also serves as a storage place for waste matter. The waste matter moves from the colon into the rectum. From there it passes out of the body through the anus during a bowel movement.

The colon has four sections: the ascending colon, the transverse colon, the descending colon, and the sigmoid colon. Cancer can start in any of the four sections or in the rectum. Each of these sections of the colon and rectum has several layers of tissues. Cancer starts in the innermost layer and can grow through some or all of the other layers. Since colon cancer and rectal cancer have many features in common, they are discussed here together.

Types of Colorectal Cancer

Before a true cancer develops, there are often earlier changes in the lining of the colon or rectum. One type of change is a growth of tissue called a polyp. Removing the polyp early may prevent it from becoming cancer.

Over 95% of colon and rectal (colorectal) cancers are adenocarcinomas. These are cancers of the cells that line the inside of the colon and rectum. There are some other, more rare, types of tumors of the colon and rectum. The facts given here refer to adenocarcinomas.

How Many People Get Colorectal Cancer?

The American Cancer Society predicts that there will be about 93,800 new cases of colon cancer and 36,400 new cases of rectal cancer in the year 2000 in this country. Colon cancer will cause about 47,700 deaths and rectal cancer about 8,600 deaths.

The death rate from colorectal cancer has been going down for the past 20 years. This may be because there are fewer cases, because more of the cases are found early, and also because treatments have improved.

Nine out of 10 people whose colorectal cancer is found and treated at an early stage, before it has spread, live at least five years. Once the cancer has spread to nearby organs or lymph nodes, the 5-year survival rate goes down.

What Causes Colorectal Cancer? Can It Be Prevented?

While we do not know the exact cause of most colorectal cancer, there are certain known risk factors. A risk factor is something that increases a person's chance of getting a disease. Some risk factors, like smoking, can be controlled. Others, such as a person's age, can't be changed.

Researchers have found several risk factors that increase a person's chance of having colorectal cancer.

Family history of colorectal cancer: Colorectal cancer seems to run in some families. For example, recent research has found an inherited tendency to develop colorectal cancer among some Jews of Eastern European descent. People with a family history suggesting a colorectal cancer syndrome should talk to their doctors about how often to have screening tests. They might also consider genetic counseling and, in some cases, genetic testing. For more information, speak with your doctor and/or refer to the ACS document on "ACS Guidelines for Screening and Surveillance for Early Detection of Colorectal Polyps and Cancer."

Personal history of colorectal cancer: Even when a colorectal cancer has been completely removed, new cancers may develop in other areas of the colon and rectum.

Personal history of polyps: Some types of polyps do not increase the risk of colorectal cancer. Other types, such as adenomatous polyps, do increase the risk of colorectal cancer, especially if they are large or there are many of them.

Personal history of inflammatory bowel disease: This condition is also called ulcerative colitis or Crohn's colitis. The colon is inflamed over a long period of time and may have ulcers in its lining. This increases the risk of colon cancer.

Aging: about 9 out of 10 people with colorectal cancer are older than 50.

Diet and obesity: A diet made up mostly of foods that are high in fat, especially from animal sources, can increase the risk of colorectal cancer. Many fruits and vegetables contain substances that interfere with the process of cancer formation. The American Cancer Society recommends eating at least five servings of fruits and vegetables every day and six servings of other food from plant sources such as breads, cereals, grain products, rice, pasta, or beans.

Being very overweight increases a person's colorectal cancer risk. Having excess fat in the waist area increases this risk more than having the same amount of fat in the thighs or hips.

Lack of exercise: being even somewhat active lowers the risk of colorectal cancer.

Even though we don't know exactly what causes colorectal cancer, there are some steps you can take to reduce your risk. First, you should follow the screening guidelines mentioned below to help detect colon or rectal cancer. When it is found and treated early, it can often be cured. Screening can also find pre-cancerous polyps. Removing these polyps helps prevent some cancers.

People who have a history of colorectal cancer in their family should check with their doctor for advice about screening tests or other tests to find cancer early.

It is important to eat plenty of fruits, vegetables, and whole grain foods and to avoid high-fat, low-fiber foods. Some studies suggest that taking a daily multivitamin containing folic acid or folate can lower colorectal cancer risk. Other studies suggest that getting more calcium with supplements or low-fat dairy products can help. Getting enough exercise is important as well. Even small amounts of exercise on a regular basis can be helpful.

Some studies have shown that use of estrogen replacement therapy (ERT) for women after menopause may reduce the risk of colorectal cancer. The overall effect of ERT is a positive one for most women, but you should talk to your doctor about the risks and benefits in your own case.

How Is Colorectal Cancer Found?

In many cases, colorectal cancer can be found early. If you have any of these symptoms, be sure to tell your doctor, especially if you are over 40 years old or if other members of your family have had the disease.

• A change in bowel habits such as diarrhea, constipation, or narrowing of the stool that lasts for more than a few days
• A feeling that you need to have a bowel movement that doesn't go away after you do
• Bleeding from the rectum or blood in the stool
• Cramping or steady stomach pain
• Decreased appetite
• Weakness and fatigue
• Jaundice (yellow-green color of the skin and white part of the eye)

Just because you have these symptoms does not mean you have cancer. But you need to talk to your doctor to be sure.

It is also possible to have colon or rectal cancer and not have any symptoms. For that reason, screening tests are used. These tests can find many cancers early and greatly improve the chances of successful treatment. Some of these tests are listed below.

Digital Rectal Exam (DRE): The doctor or health care provider inserts a gloved finger into the rectum to feel for anything not normal. This simple test, which is not painful, can detect many rectal cancers.

Fecal Occult Blood Test (FOBT): In this context, the word occult means hidden. The FOBT is used to find small amounts of blood in the stool that can't normally be seen. A sample of stool is tested for traces of blood. People having this test will receive a test kit with instructions that explain how to take a stool sample at home. The kit is then sent to a lab for testing.

Sigmoidoscopy: A slender, lighted tube is placed in the rectum. This allows the doctor to look at the inside of the rectum and part of the colon for cancer or polyps.

Colonoscopy: A longer, flexible tube is placed through the rectum into the colon. It is long enough to reach the full length of the colon. The tube is linked to a video camera and display. The doctor can look at the picture to find cancer or polyps. Because the tube is longer, the doctor is able to see much more of the colon's lining. Polyps can be removed using a wire loop that goes through the tube. Pieces of the polyp can be sent to a lab to see if cancer cells are present. If the doctor sees anything unusual, a biopsy may be done. A small piece of tissue is taken out through the colonoscope. The tissue is sent to the lab to see if it is cancerous or benign.

Barium Enema (double contrast barium enema or barium enema with air contrast): An enema of a chalky substance is used to partly fill up and open the colon. Air is then added to expand the colon. After that, x-ray films are taken.

American Cancer Society Guidelines For the Early Detection of Colon or Rectal Cancer

For people of average risk with no symptoms, beginning at age 50, both men and women should follow one of the three screening options below:

• Yearly fecal occult blood test plus flexible sigmoidoscopy every 5 years*
  or
• Colonoscopy every 10 years*
  or
• Double contrast barium enema every 5-10 years*.

*A digital rectal examination (DRE) should be performed at the time of each screening sigmoidoscopy, colonoscopy or barium enema.

People should begin screening earlier and have it more often if they have any of these risk factors:

• A strong family history (mother, father, sisters, or brothers) of colon or rectal cancer or polyps.
• A family history of hereditary colorectal cancer syndromes
• A personal history of colon or rectal cancer or chronic inflammatory bowel disease.

If Colorectal Cancer Is Suspected

If your doctor has any reason to suspect colon or rectal cancer, the doctor will look at your medical history and do a physical exam. Then you will need to have further tests. Some of these tests are the same ones that are used for screening people who do not have symptoms.

Colonoscopy: See the section on finding colon cancer for information about this test. If the doctor sees something suspicious, a sample will be taken for examination under a microscope. Sometimes small polyps may be entirely removed through the scope. If the abnormal area is larger, a biopsy will be done. During a biopsy, a small sample of tissue is removed and sent to the lab.

Barium enema with air contrast: This test was explained in the earlier section.

Ultrasound: Ultrasound uses sound waves to produce a picture of the inside of the body. Most people know about ultrasound because it is often used to view a baby during pregnancy. Two special types of ultrasound might be used for people with colon or rectal cancer. In one, the instrument that gives off sound waves is placed into the rectum. In the other test, used during surgery, the instrument is placed against the surface of the liver to see if the cancer has spread there.

CT scan (computed tomography): A CT (or CAT) scan uses x-rays to take many pictures of the body that are then combined by a computer to give a detailed cross-sectional image. Spread of colorectal cancer to internal organs such as the liver or lungs, or elsewhere can often be found by a CT scan.

Chest x-ray: This test may be done to see whether colorectal cancer has spread to the lungs.

Magnetic resonance imaging (MRI): Like computed tomography, MRI displays a cross-section of the body. However, MRI uses powerful magnetic fields instead of radiation.

Angiography: For this test, a tube is placed into a blood vessel and moved until it reaches the area to be studied. Then a dye is injected and a series of x-ray images is taken. When the pictures are complete, the tube is removed. Angiography is sometimes used by surgeons to assist in planning the surgery.

Blood tests: These tests can be used to monitor the effects of chemotherapy or to look for spread of the cancer to the liver and the bones.

CEA blood test (Carcinoembryonic antigen) blood test: This test is most often used with other tests for follow-up of patients who already have had colorectal cancer and have been treated. CEA may be useful to provide an early warning of a cancer that has returned. Because the CEA level in the blood can be high for reasons other than cancer, or it may be normal in a person who has cancer, it is not used as a method for finding cancer in people who have never had a cancer and appear to be healthy.

After the Tests: Staging

Staging is the process of finding out how far the cancer has spread. This is very important because your treatment and the outlook for your recovery depend on the stage of your cancer. For early cancer, surgery may be all that is needed. For more advanced cancer, other treatments such as chemotherapy or radiation therapy may be required. Be sure to ask your doctor to explain the stage of your cancer so that you can make the best choice for yourself about your treatment.

There is more than one system for staging colon or rectal cancer. Some use numbers and others use letters. But all systems describe the spread of the cancer through the layers of the wall of the colon or rectum. They also take into account whether the cancer has spread to nearby organs or to organs farther away.

In general, a lower number or letter means the cancer has spread less. A higher number or letter means the cancer is more serious. For example, a stage I cancer is less widespread. A higher number, for example stage IV, means a more serious stage of the disease. Ask your doctor to explain the stage of your cancer in a way you can understand.

Treatment For Colorectal Cancer

The treatment of colon and rectal cancer are very much alike. When they differ, it will be noted.

There is a lot for you to think about when choosing the best way to treat or manage your cancer. Often there is more than one treatment to choose from. You may feel that you need to make a decision quickly. But give yourself time to absorb the information you have learned. Talk to your cancer care team. Look at the list of questions at the end of this piece to get some ideas. Then add your own.

You may want to get a second opinion. Your doctor should not mind your doing this. In fact, some insurance companies require you to get a second opinion. You may not need to have tests done again since the results can often be sent to the second doctor. If you are in an HMO (health maintenance organization), find out about their policy concerning second opinions.

The three main types of treatment for colorectal cancer are surgery, radiation therapy, and chemotherapy. Depending on the stage of the cancer, two or even three types of treatment may be used at the same time or one after the other.

Surgery for Colon Cancer

Surgery is the main treatment for colon cancer. Usually, the cancer and a length of normal tissue on either side of the cancer (as well as nearby lymph nodes) are removed. The two ends of the colon are then sewn back together. For colon cancer, a colostomy (an opening in the abdomen for getting rid of body wastes) is not usually needed, although sometimes a temporary colostomy may be done.

Sometimes very early colon cancer can be removed through a colonoscope. When this is done, the doctor does not have to cut into the abdomen. For some very advanced cancers and for some patients in poor health, a different operation might be done to relieve symptoms such as blockages and bleeding.

Surgery for Rectal Cancer

Surgery is usually the main treatment for rectal cancer, although radiation therapy may also be used in addition to surgery. There are several types of surgery for rectal cancer.

Polypectomy is a method used to remove mushroom-like growths that contain early stage cancer. The cancer is cut out across the base of the polyp's stalk.

Local excision removes superficial cancers and a small amount of nearby tissue from the inner layer of the rectum.

Local transanal resection involves cutting through all layers of the rectum to remove invasive cancers as well as some surrounding normal rectal tissue.

All four of the above methods can be done without cutting through the abdomen.

For some early and most advanced stages of rectal cancer, other types of surgery may be done. A low anterior (LA) resection is used for cancers near the upper part of the rectum, close to where it connects with the colon. After this operation waste is eliminated in the usual way.

For cancers in the lower part of the rectum, close to its outer connection to the anus, an abdominoperineal (AP) resection is done. After this surgery, a colostomy is needed. A colostomy is an opening of the colon in the front of the abdomen. It is used for the elimination of body waste.

A pelvic exenteration removes the rectum as well as nearby organs such as the bladder, prostate, or uterus if the cancer has spread to these organs. A colostomy is needed after this operation. If you are having this surgery, ask your doctor or nurse about follow-up care.

If the colorectal cancer has spread to only a few areas in other organs such as the lungs, liver, or ovaries, surgery or some other method might be used to destroy the cancer cells.

Radiation Therapy for Colon and Rectal Cancer

Radiation therapy is treatment with high energy rays (such as x-rays) to kill or shrink cancer cells. The radiation may come from outside the body (external radiation) or from radioactive materials placed directly in the tumor (internal or implant radiation).

After surgery, radiation can kill small areas of cancer that may not be seen during surgery. If the size or location of a tumor makes surgery hard, radiation my be used before the surgery to shrink the tumor. Radiation also may be used to ease (palliate) symptoms of advanced cancer such as intestinal blockage, bleeding, or pain.

External radiation is most often used for people with colon or rectal cancer. Treatments are given five days a week for several weeks. Each treatment lasts only a few minutes and is something like having an x-ray for a broken bone.

A different approach may be used for some cases of rectal cancer. The radiation can be aimed through the anus and reaches the rectum without passing through the skin of the abdomen.

Side effects of radiation therapy for colon or rectal cancer include mild skin irritation, nausea, diarrhea, or tiredness. These often go away after a while. If you have these or other side effects, talk to your doctor. There are ways to lessen many of these problems.

Chemotherapy for Colon and Rectal Cancer

Chemotherapy refers to the use of drugs to kill cancer cells. Usually the drugs are given into a vein or by mouth. Once the drugs enter the bloodstream, they reach all parts of the body. Studies have shown that chemotherapy after surgery can increase the survival rate for patients with some stages of colorectal cancer. Chemotherapy can also help relieve symptoms of advanced cancer.

Chemotherapy can have some side effects. These side effects will depend on the type of drugs given, the amount taken, and how long treatment lasts. Side effects could include nausea and vomiting, loss of appetite, loss of hair, hand and foot rashes, and mouth sores. Most of the side effects go away when treatment is over. Anyone who has problems with side effects should talk with their doctor or nurse, as there are often ways to help.

Clinical Trials

Studies of new treatments in patients are known as clinical trials. A clinical trial is only done when there is some reason to believe that the treatment being studied may be of value to the patient. The main questions the researchers want to answer are:

• Does this treatment work?
• Does it work better than the one we're now using?
• What side effects does it cause?
• Do the benefits outweigh the risks?
• Which patients are most likely to find this treatment helpful?

During your course of treatment, your doctor may suggest that you look into a clinical trial. This does not mean that you are being asked to be a human guinea pig. Nor does it mean that your case is hopeless. However, there are some risks. No one knows in advance if the treatment will work or exactly what side effects will occur. That's what the study is designed to find out. Keep in mind that standard treatments, too, can have side effects.

Clinical trials are carried out in steps called phases. Each phase is designed to answer certain questions. Ask you doctor if there is a clinical trial that might be right for you. Then learn all you can about that trial. Because you volunteer to take part in a clinical trial, you can leave the trial at any time.

To learn more about clinical trials, call the National Cancer Institute at 1-800-4-CANCER or visit the NCI website for patients at cancertrials.nci.nih.gov

Alternative and Complementary Therapies

There is a great deal of interest these days in alternative and complementary treatments for cancer. Before changing your treatment or adding any methods of your own, be sure to talk to your doctor or nurse. Some methods can be safely used along with standard medical treatment. Others, however, can interfere with standard treatment or cause serious side effects. That is why it's important to talk openly with your doctor. You can also call the American Cancer Society at 1-800-ACS-3245 for more information about specific methods.

Some Questions to Ask Your Doctor

As you cope with cancer and cancer treatment, you need to have honest, open discussions with your doctor. You should feel free to ask any question that's on your mind, no matter how small it might seem. Here are some questions you might want to ask. Be sure and add your own.

• Would you please write down the exact kind of cancer I have?
• Where is my cancer located?
• Has it spread beyond the place where it began?
• What is the stage of my cancer, and what does that mean in my case?
• What treatment choices do I have?
• What treatment do you suggest and why?
• What is the goal of this treatment?
• Will I need a colostomy?
• What risks or side effects are there to the treatments you suggest?
• If I will lose my hair, where can I get a wig?
• What are the chances my cancer will come back with this treatment plan?
• What are my chances of survival, based on my cancer as you see it?
• What should I do to be ready for treatment?
• Should I follow a special diet?

WHAT HAPPENS AFTER TREATMENT FOR COLORECTAL CANCER?

Each type of treatment for cancer has side effects that may last for a few months; some may be permanent. You may be able to hasten your recovery by being aware of the side effects before you start treatment. You might be able to take steps to reduce them or shorten the length of time they last.

Remember that your body is unique, and so are your emotional needs and your personal circumstances. In some ways, your cancer is like no one else's. No one can predict how your cancer will respond to treatment. Statistics can paint an overall picture, but you may have special strengths such as a healthy immune system, a strong family support system, or a deep spiritual faith. All of these have an impact on how you cope with cancer.

Cancer treatment can make you feel tired. You need to give yourself time to recover. Don't feel you have to rush back to work or resume all of your normal activities right away.

Do as much as you can to help yourself stay healthy and active. If you smoke, try to quit. Ask your doctor or nurse for ideas about how to quit smoking. Eat a balanced diet of healthy foods, including plenty of fruits, vegetables, and whole grains. Ask your cancer care team if you could benefit from a special diet -- they may have specific recommendations for people who have had radiation therapy, a colostomy, or other colorectal surgery. Once you get your strength back, try to exercise a few hours each week. Check with your doctor before you start an exercise program. Your doctor can suggest the types of exercise that are right for you.

Your doctor or nurse can suggest other resources that might help you during your recovery from treatment. There are many support groups that provide emotional support, friendship, and understanding.

Surgery and radiation therapy may sometimes affect a person's feelings about their body, and may lead to specific physical changes that affect sexuality. Your cancer care team can help with these issues, so don't hesitate to share your concerns.

Follow-up care: For years after treatment ends, regular follow-up exams will be very important for you. These can show if the cancer has come back. Be sure to report any symptoms to your doctor right away. Follow-up usually includes a careful physical exam and rectal exam, colonoscopy, and blood tests. Other imaging studies such as chest x-rays, CT scans, and MRI scans may also be done if symptoms or other test results suggest that the cancer has come back.

For people with colostomies: A permanent colostomy is seldom needed now in the treatment of colon cancer. Most colostomies are done for cancers that are near the outer or lower end of the rectum. If you have a colostomy, follow-up is an important concern. You may feel worried or isolated from normal activities. Whether your ostomy is temporary or permanent, there are nurses who can teach you about the care of your colostomy. Ask the American Cancer Society about programs offering information and support in your area.