Considering the Facts About Colorectal Cancer 
Monday, 06 March 2006 

Cancer is the second leading cause of death in the U.S. and it can affect virtually every part of the body. Among the most commonly diagnosed cancers are those of the colon and rectum, which are part of our digestive or gastrointestinal system.

Nearly 150,000 people in the U.S. are expected to be diagnosed with colorectal cancer this year, and more than 50,000 will die of the disease.

Colorectal cancer is a topic most people would probably prefer to avoid even thinking about. That, however, can be a dangerous or even fatal mistake.  Recommended tests and screenings and early treatment may significantly reduce the risks from colorectal cancer and improve patient outcomes.

What is Colorectal Cancer?

Colorectal cancer occurs when abnormal cells begin to grow in one of the four segments of the colon or in the rectum, which adjoins the anus where waste fecal matter passes out of the body. The colon and rectum have several layers of tissue. Colorectal cancers begin in the innermost layer and can grow through some or all of the other layers.  While this process can take several years, we know that most colorectal cancers begin as a small pre-cancerous growth known as a polyp. Left untreated, colon cancer can cause dangerous blockages of the intestines and spread to other parts of the body.

Who is at Risk of Getting Colorectal Cancer?

While anyone can get colorectal cancer, there are several factors that may affect a person’s likelihood of contracting the disease:

Family History: If you have close relatives (parent or siblings) who have contracted colorectal cancer, your risk of developing the disease is doubled. There also are hereditary factors that account for a small percentage of colorectal cancers.

Aging: Colorectal cancer is more common among people over 50. The median age at diagnosis of colorectal cancer in the U.S. is 70 for men and 73 for women.

Diet: People whose diets consist mostly of foods that are high in fat – especially animal fat – may be at increased risk for colorectal cancer. Many doctors recommend eating high-fiber foods and plenty of fruits and vegetables, which contain substances that interfere with the process of cancer formation.

Lack of Exercise: People who are not physically active have an increased risk of developing colorectal cancer.  The American Cancer Society recommends that people engage in moderate exercise for at least 30 minutes, four to five times a week.

Obesity: Overweight people are at greater risk of developing colorectal cancer. Researchers believe the excess fat may change metabolism and encourage the growth of abnormal cells in the colon and rectum.

Smoking: The link between smoking and cancers of the lungs, mouth and esophagus is well known. But recent studies suggest that smokers may be up to 40 percent more likely to develop colorectal cancers than non-smokers. That’s because some harmful substances from smoking are swallowed and pass through the digestive system, where they can cause damage.

History of Colorectal Cancer: People, who already have had colon or rectal cancer, even if it’s been totally removed, have a heightened risk of developing the disease. This is especially true if the initial cancer occurred when the patient was young.

History of Intestinal Polyps: Since most colorectal cancers start as polyps, people who have been diagnosed and treated for polyps are more likely to develop colorectal cancer. Increased screening and monitoring is often recommended.

History of Chronic Bowel Disease: People with a history of chronic inflammatory conditions such as ulcerative colitis or Crohn’s Disease have an increased risk of colon cancer. For such patients, doctors often recommend that screening start earlier and be done more frequently.

Can Colorectal Cancer Be Prevented?

While there’s no way to guarantee someone will avoid colorectal cancer, people may lower their risks of the disease by being aware of and managing the factors noted above. We can’t change our heredity, but we can improve our diet, get proper exercise, avoid smoking and watch our weight. Another step people can take is to undergo screening for signs of the disease.


Statistics show that the risks of colorectal cancer can be reduced through early detection, and the key to that is timely screenings. There are several ways doctors can look for signs of the disease, and some of these tests are recommended even if you do not have symptoms or a history of the disease. Your doctor can tell you which of these tests may be appropriate for you.

Digital Rectal Examination: The doctor inserts a gloved finger into the rectum to feel for abnormalities. This simple test, which causes only slight discomfort, can detect tumors affecting the anus and lower rectum. Many doctors perform this test in routine annual exams.

Fecal Occult Blood Test: Used to find hidden blood in feces, this test can be done in a doctor’s office at the time of a regular exam or at home. It involves taking small samples of a patient’s stools, which are sent to a laboratory for analysis. Polyps or other abnormalities can cause hidden blood in the stool.

Sigmoidoscopy: A slender, flexible tube is inserted through your rectum into the lower part of the colon. The lighted instrument, often equipped with a video camera, allows the doctor to search for abnormalities in the lower half of the colon. The procedure should not be painful although it may cause some discomfort.

Colonoscopy: Using what is essentially a longer version of the sigmoidoscope, the colonoscopy allows the doctor to see the entire colon. In addition to its diagnostic value, the procedure allows the doctor to remove polyps that may be found or conduct a biopsy of any larger growths that are discovered. The procedure is normally done with the patient under sedation.


Treatment for colorectal cancer may vary from patient to patient, but the usual approach involves surgery. Typically, the cancer and a length of normal tissue on either side are removed, and the remaining sections are re-attached. In some cases, the surgeon may perform a colostomy, which involves attaching the colon to an opening in the abdomen for getting rid of body wastes.  If the cancer is caught early, the doctor may be able to perform the surgery using the colonoscope rather than cutting into the abdomen.

Radiation and drugs also are used to treat colorectal cancers. Radiation therapy uses high-energy rays to destroy cancer cells.  Chemotherapy involves cancer-fighting drugs that can increase survival rates after surgery. Doctors are constantly evaluating new radiation and drug therapies as they search for ways to prolong and improve their patients’ lives.

Symptoms of Colorectal Cancer

Warning signs to report to your doctor include:

  • Any change in bowel habits
  • Diarrhea or constipation
  • Blood on or in 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 doesn’t completely empty
  • Weight loss with no known reason
  • Constant tiredness

For more information on colorectal cancer, contact your physician or visit