Colorectal Cancer Questions & Answers

Q: What is colorectal cancer?

A: Cancer is an abnormal and uncontrolled growth of cells in the body. "Colorectal" refers to the colon and rectum, which together make up the large intestine. Colorectal cancer can originate anywhere in the large intestines. The majority of colorectal cancers develop first as polyps, abnormal growths inside the colon or rectum that may become cancerous.

Q: What is screening?

A: Screening is when a test is used to look for a disease before there are any symptoms. Cancer screening tests are effective when they can detect diseases early and lead to more effective treatment or when they can detect disease before it has become cancer and prevent the development of cancer.

Q: What causes colorectal cancer?

A: The exact cause of most colorectal cancers is not yet known, however research has established that approximately 75% of colorectal cancers occur in people with no known risk factors. Risk factors that may increase a person's risk of developing colorectal cancer include

• A personal or family history of colorectal polyps or colorectal cancer, or

• Inflammatory bowel disease (Ulcerative colitis or Crohn's disease), or

• Genetic syndromes such as familial adenomatous polyposis (FAP) or hereditary nonpolyposis colon cancer (HNPCC). (Just 5% of colorectal cancers are linked to these genetic syndromes.)

Q: How does colorectal cancer affect the U.S. population?

A: Colorectal cancer is the 2nd leading cancer killer in the United States. In 2004, the American Cancer Society estimates that 146,940 people in the U.S. will be diagnosed with colorectal cancer and 56,730 people will die of the disease.¹

¹Source: Cancer Facts and Figures 2004, American Cancer Society, 2004.

Q: Who is at risk to develop colorectal cancer?

A: Colorectal cancer occurs in men and women of all racial and ethnic groups. Approximately 75% of colorectal cancers occur in people with no known risk factors. Here are other important facts about who is at risk for developing colorectal cancer

• Most colorectal cancers - more than 90% - are diagnosed in people aged 50 years or older. The risk for developing colorectal cancer increases with age.

• A family history of colorectal cancer or colorectal polyps increases a person's risk of developing colorectal cancer.

• Certain diseases of the intestines, including inflammatory bowel disease (Ulcerative colitis or Crohn's disease), can increase the risk for colorectal cancer.

Q: Is there anything I can do to reduce my risk for colorectal cancer?

A: There is strong scientific evidence that having regular screening tests for colorectal cancer beginning at age 50 reduces deaths from colorectal cancer. Screening tests can find precancerous polyps (abnormal growths) in the colon and rectum, and polyps can be removed before they turn into cancer. In this way, colorectal cancer is prevented.

Studies have also shown that increased physical activity and maintaining a healthy weight can decrease the risk for colorectal cancer. Evidence is less clear about other ways to prevent colorectal cancer. Research is underway to determine whether dietary changes may decrease the risk for colorectal cancer. Currently there is no consensus on the role of diet in preventing colorectal cancer, however, medical experts recommend a diet low in animal fats and high in vegetables, fruits, and whole grain products to reduce the risk of other chronic diseases, such as coronary artery disease and diabetes. It may also reduce the risk of colorectal cancer. In addition to studying dietary changes, researchers are examining the role of certain medications and supplements, including aspirin, calcium, vitamin D and selenium, in preventing colorectal cancer. However, the most effective way to reduce your risk of colorectal cancer is by having colorectal cancer screening tests beginning at age 50.