What is Colorectal Cancer?

Colorectal cancer is cancer of the colon or rectum. The colon and rectum are part of the body's digestive system. The purpose of the digestive system is to remove nutrients such as vitamins, minerals and proteins from the food you eat so your body can use them. The colon and rectum then store the waste until it passes out of the body. The digestive system includes the esophagus, stomach, and the small and large intestines. The last 6 feet of the large intestine is called the large bowel or colon. The last 8 or so inches of the colon is the rectum.

Like other parts of the body, the colon and rectum are made up of many types of cells. Cells divide in an orderly, controlled way to produce more cells when more cells are needed in the body. When cells divide in an abnormal, uncontrolled way, they can form either a benign or malignant tumor.

Benign tumors are not cancerous. In the colon and rectum, a polyp is a benign tumor that may form. Because they can become cancerous, polyps should be removed.

Malignant tumors are cancerous. Cancer cells can spread to nearby healthy cells and destroy them. The cancerous cells can also invade other parts of the body. Cancerous cells in the colon and rectum can spread to the lymph glands which are located nearby. The cancer can also spread to other parts of the body.

Like many diseases, colorectal cancer is best treated when it is detected early. Because of this, people who are at higher risk for this cancer should have screening tests regularly.

• One screening test is a digital rectal exam: the physician inserts a lubricated, gloved finger into the rectum to feel for abnormal areas.

• People who are over age 50 should have an annual fecaloccult test, in which a small amount of stool is tested for hidden blood. Other conditions can also lead to bleeding, so blood in the stool does not necessarily mean cancer.

• The National Cancer Institute recommends that beginning at age 50, people also have a sigmoidoscopy every 3 to 5 years. During this test, the doctor looks through a thin, lighted tube to check for tumors, polyps, or other abnormalities. Talk to your physician about what screening is appropriate for you.

• Changes in bowel habits

• Blood in the stool (bright red or very dark red)

• Diarrhea or constipation

• Weight loss or loss of appetite

• Constant fatigue

• Frequent stomach/abdominal discomfort such as bloating, fullness,gas or cramps

• Feeling that the bowel does not completely empty

• Stools that are narrower than usual.

Any of these symptoms may also be due to other problems, such as ulcers, an inflamed colon, or hemorrhoids. Still, it is important to see a doctor if any of these problems exist. A doctor who specializes in treating digestive problems is called a gastroenterologist.

If tests show abnormal growth in the colon or rectum, the doctor will need to do a biopsy. A biopsy is a test in which some cells are removed from the abnormal growth. These cells are then examined under a microscope to check for cancer. If a biopsy reveals cancer, the doctor may also take x-rays and do ultrasonography or CT scans (CAT scans) of the lungs and liver because the cancer can spread to these areas. Blood tests may be used to provide more information about the cancer.

The risk of colorectal cancer appears to increase with age, with the risk rising sharply at the ages of 50 to 55 and peaking at age 75. If you or your family has a history of colorectal cancer or polyps, or a condition called inflammatory bowel disease, you may have an increased risk of colorectal cancer. Removal of pre-cancerous polyps called adenomas may be an effective way to prevent the development of cancer.

Studies show that colorectal cancer probably results from a combination of factors, including inherited susceptibility and other factors such as diet. A high-fat, low-fiber diet appears to be a major risk factor in colorectal cancer. The rates of colon cancer are high in areas where people tend to eat a diet that is high in fat. In countries where rates of colorectal cancer are high, 40to 50 percent of the calories consumed are from fat.

A diet that is high in fiber, particularly fruit and vegetable fiber, appears to protect against colorectal cancer. Calcium in the diet, as well as other nutrients, may also inhibit colorectal cancer.

Physical activity and the use of non-steriodal anti-inflammatory drugs such as aspirin and ibuprofen may reduce the risk of this disease. For women who are past menopause, estrogen replacement therapy may also reduce the risk.

Treatment for Colorectal Cancer

The doctor is the best person to answer questions about treatment. The choice of treatment options for each patient will depend upon the stage of the disease (whether it is just in the lining of the colon or rectum or if it has spread to other places), and the patient's general state of health.

Several kinds of treatment are available. Surgery is the most common treatment for all stages of colorectal cancer. Radiation therapy, chemotherapy and biological therapy are also used for treating this disease.

If the cancer is detected early enough, surgery is often the only treatment needed for colorectal cancer. Most patients have a partial colectomy, in which a surgeon removes thepart of the colon or rectum where the cancer is located as well as some of the surrounding tissue. Nearby lymph nodes are usually removed so that a pathologist can examine them under a microscope. If cancer has reached the nodes, additional treatment is needed.

When the healthy sections of the colon or rectum can be reconnected, the procedure is called anastomosis. When they cannot be reconnected, the doctor creates an opening called a stoma in the abdominal wall. This procedure is called a colostomy. The patient then uses a special bag to collect the waste.

Sometimes a colostomy is temporary -- just until the colon or rectum heals after surgery. Then the sections of colon or rectum can be reconnected and the stoma can be closed. When the tumor is in the rectum, a permanent colostomy may be needed.

Radiation therapy is the use of high-energy rays to attack cancer cells. Like surgery, it only affects cancer in the areas that are treated. Sometimes, a combination of radiation and chemotherapy are used to shrink the tumor before it is surgically removed or to destroy remaining cancer cells after surgery. Radiation therapy can also be used to alleviate pain when tumors cannot be removed with surgery.

In chemotherapy, drugs are used to kill cancer cells. These drugs travel through the body in the blood. Chemotherapy can be used after surgery to help prevent the cancer from spreading. This is called adjuvant therapy. When a tumor cannot be completely removed with surgery, chemotherapy can help relieve symptoms or control the cancer growth.

Biological therapy helps the body's immune system to destroy cancer cells. Sometimes biological therapy and chemotherapy are both used after surgery as adjuvant therapy.

Patients should consult with a specialist to learn about all the treatment options as well as their side effects before making a decision. It may help to have a second opinion. Some insurance companies now require a second opinion. Specialists who treat colorectal cancer include surgeons, oncologists, and gastroenterologists.

General Questions

The colon and rectum are part of the digestive system. Together, they form a long, muscular tube called the large intestine (also called the large bowel). The colon is the upper 5 to 6 feet of the large intestine, and the rectum is the last 6 to 8 inches.

The anus is the opening to the rectum. After food is digested in the stomach and small intestine, it moves into the colon, where any remaining water is absorbed into the body, leaving solid waste (called stool). Stool moves through the colon and rectum and leaves the body through the anus.

1. How do I prevent colon-rectal (colorectal) cancer?

ANSWER:
Colorectal cancer is one of the most common types of cancer in the United States, scientists are trying to learn more about what causes the disease and how it can be prevented.

Although doctors do not yet know why one person gets colorectal cancer and another does not, they do know that no one can catch colorectal cancer from another person. Cancer is not contagious.

People can lower their risk of getting colorectal cancer. For example, those who have colorectal polyps (a nodular growth of tissue developing in the lining of a cavity, may be benign or malignant), should talk with the doctor about having them removed. People can also change their eating habits to cut down on fat and increase the amount of fiber (roughage) in their diet.

2. What are the risk factors for developing colorectal cancer?

• Polyps. Most -- perhaps all -- colorectal cancers develop in polyps. Polyps are benign, but they may become cancerous over time. Removing polyps is an important way to prevent colorectal cancer.

• Age. Colorectal cancers occur most often in people who are over the age of 50, and the risk increases as people get older.

• Family history. Close relatives of a person who has had colorectal cancer have a higher than average risk of developing the disease. The risk for colon cancer is even higher among members of a family in which many relatives have had it. (In such cases, the disease is called familial colon cancer.)

• Familial polyposis. This is an inherited condition in which hundreds of polyps develop in the colon and rectum. Over time, these polyps can become cancerous. Unless the condition is treated a person who has familial polyposis is almost sure to develop colorectal cancer.

• Diet. The risk of developing colon cancer seems to be higher in people whose diet is high in fat, low in fruits and vegetables, and low in high-fiber foods such as whole-grain breads and cereals.

• Ulcerative colitis. This disease causes inflammation of the lining of the colon. The risk of colon cancer is much greater than average for people who have this disease, and the risk increases with the length of time they have had it.

      3. What can I do to detect it?

ANSWER:
Most health problems respond best to treatment when they are diagnosed and treated as early as possible. This is especially true of colorectal cancer. Treatment is most effective before the disease spreads.

People can take an active role in the early detection of colorectal cancer by following these guidelines: 

• During regular checkups, have a digital rectal exam. For this exam, the doctor inserts a lubricated, gloved finger into the rectum and feels for abnormal areas.

• Beginning at age 40, have an annual fecal occult blood test. This test is a check for hidden (occult) blood in the stool. The test is done because colorectal cancer may cause bleeding that cannot be seen. However, other conditions also may cause bleeding, so having blood in the stool does not necessarily mean a person has cancer.

• Beginning at age 50, have a sigmoidoscopy every 3 to 5 years. (Speak with your doctor.) This is an exam of the rectum and lower colon using a sigmoidoscope. The doctor looks through a thin, lighted tube to check for polyps, tumors, or other abnormalities.

• A change in bowel habits

• Diarrhea or constipation

• Blood in or on the stool (either bright red or very dark in color)

• Stools that are narrower than usual

• General stomach discomfort (bloating, fullness, and/or cramps)

• Frequent gas pains

• A feeling that the bowel does not empty completely

• Weight loss with no known reason

• Constant tiredness

      5. How will I be diagnosed for colorectal cancer?

• Lower GI series: X-rays of the colon and rectum (the lower gastrointestinal tract). The x-rays are taken after the patients is given an enema with a white, chalky solution containing barium. (This test is sometimes called a barium enema.) The barium outlines the colon and rectum on the x-rays, helping the doctor find tumors or other abnormal areas. To make small tumors easier to see, the doctor may expand the colon by carefully pumping in air during the test. This is called an air contrast or double-contrast barium enema.

• Colonoscopy: An examination of the inside of the entire colon using a colonoscope, an instrument similar to a flexible sigmoidoscope, but longer.

6. What do I need to know about the treatment for colorectal cancer?

• What is the stage of the disease?

• What are my treatment choices? Which do you suggest for me? Why?

• Would a clinical trial be appropriate for me?

• What are the expected benefits of each treatment?

• What are the risks and possible side effects of each treatment?

• What can be done about side effects?

• What can I do to take care of myself during therapy?

• What is the treatment likely to cost?

Patients and their loved ones are naturally concerned about the effectiveness of the treatment. Sometimes they use statistics to try to figure out whether the patient will be cured, or how long her or she will live. It is important to remember, however, that statistics are averages based on large numbers of patients. They cannot be used to predict what will happen to a particular person because no two cancer patients are alike.

People should feel free to ask the doctor about the chance of recovery (prognosis), but even the doctor does not know for sure what will happen. When doctors talk about surviving cancer, they may use the term remission rather than cure. Even though many patients recover completely, doctors use this term because the disease can come back.

• Your doctor may be able to suggest a doctor who specializes in treating colorectal cancer. Specialists who treat this disease include surgeons, medical oncologists, gastroenterologists, and radiation oncologists.

• Patients can get the names of doctors from their local medical society, a nearby hospital, or a medical school.

• Cancer information lines can tell callers about treatments facilities, including cancer centers and other National Cancer Institute supported programs.

• A temporary colostomy is sometimes needed to allow the lower colon or the rectum to heal after surgery. Later in a second operation, the surgeon reconnects the healthy sections of the colon or rectum and closes the colostomy. The patientís bowel functions soon return to normal.

• A permanent colostomy may be necessary when the tumor is in the rectum. A few patients who has cancer in the lower colon may also require a permanent colostomy.

       9. What should I know before surgery?

• What kind of operation will it be?

• How will I feel afterward? If I have pain, how will you help me?

• Will I need a colostomy? Will it be temporary or permanent?

• How long will I be in the hospital?

• Will I have to be on a special diet? Who will teach me about my diet?

• When can I return to my regular activities?

• Will I need additional treatment?