AMITA Health Endoscopy Center Lincoln Park

Colorectal Cancer Screening

Overview

Colorectal cancer (CRC) involves the large intestine (colon) and rectum. The last several inches of the large intestine are called the rectum. Cancer forms in the inner lining of the intestine wall. 150,000 people will be diagnosed, and 50,000 people will die each year in the United States from CRC.

Risk factors for CRC include:

  • Adenomatous polyps (clumps of intestinal lining cells) inside the colon and rectum that may turn cancerous
  • Age 45 or older
  • High-fat diet and low-fiber diet
  • Lack of physical activity
  • Obesity
  • Diabetes
  • Smoking and alcohol-use
  • Inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease
  • Family history of CRC or polyps, familial adenomatous polyposis (FAP), or hereditary non-polyposis colorectal cancer (Lynch syndrome)
  • History of radiation therapy for cancer

Screening Options

Many patients are reluctant to get some screening tests done due to embarrassment or discomfort from the procedure. It’s important to remember that these issues are temporary, and screening can save your life.

  • Colonoscopy. A long, flexible tube with a light and camera is inserted into the rectum after sedation is given. The camera allows the doctor to view and detect polyps and cancer.
    • Pros – Colonoscopy is one of the most sensitive tests for CRC screening. Polyps and other tissue samples (biopsies) can be removed through the colonoscope. Your doctor can view the entire colon and rectum and not just the lowest parts. In comparison, a sigmoidoscopy can only see parts of the descending colon and the rectum.
    • Cons – The colon must be thoroughly cleansed before the procedure, and your diet must be changed before the test. Medications may need to be adjusted. You’ll need someone to drive you due to sedation. Occasional bleeding from where tissue is removed. Possible cramping and bloating after the procedure.
  • Sigmoidoscopy. A shorter, flexible tube with a light and camera is inserted into the rectum. The camera allows the doctor to view and detect polyps and cancer.
    • Pros – Sigmoidoscopy is very sensitive in detecting CRC in the last portion of the large intestine.
    • Cons – The sigmoidoscope can only visualize parts of the descending colon and the rectum, not the entire large intestine. Similar to a colonoscopy, the colon must be thoroughly cleansed before the procedure, and your diet must be changed before the test. Medications may need to be adjusted. Occasional bleeding from where tissue is removed. Possible cramping and bloating after the procedure.
  • Fecal Occult Blood Testing or Fecal Immunochemical Testing. Both tests check your stool for hidden or occult blood.
    • Pros – Stool sample can be collected at home. No sedation. No cleansing or emptying the colon ahead of time.
    • Cons – The colon lining cannot be visualized, and the tests fail to detect some polyps and cancers. Foods might need to be avoided before the test. If blood is detected, further testing will probably be needed, including colonoscopy. False-positive results (suggest abnormality when none present).
  • Stool DNA Testing. Everyone has seen the commercials and ads. These tests look for DNA in your stool that might indicate cancer or precancerous cells, as well as blood.
    • Pros – Collect stool at home. No bowel cleansing or sedation. Normal diet and medications before the test.
    • Cons – The colon lining cannot be visualized. Less sensitive than colonoscopy, especially for precancerous polyps. False-positive results. If abnormal, further testing will probably be needed, including colonoscopy.
  • CT Colonography or Virtual Colonoscopy. This imaging test is a CT or CAT scan used to detect changes in the colon and rectum.
    • Pros – No sedation or colonoscope inserted into the rectum.
    • Cons – You still need a catheter placed in the rectum to insert air and can have cramping and bloating after. Bowel cleansing and diet changes are necessary. Medications may need to be adjusted. Radiation exposure. If abnormality is seen, colonoscopy may be required anyway.

Conclusion

Talk with your provider and be sure to firmly commit to the appropriate screening test.