The Colorectal Conundrum– Studies Show Screening Works but Many Still Not Screened

Posted on February 5th, 2009 by

In spite of demonstrated benefits, many people are failing to receive recommended screening for colorectal cancer. Colorectal cancer screening is central to identification and prevention of the disease: It can detect cancer at an early stage and can also prevent cancer by allowing physicians to detect and remove precancerous polyps.

How It’s Done

There are several screening tests for the early identification of colorectal cancer. The choice of which test to use, or which combination of tests, will need to be made in consultation with your doctor. Available tests include the following:

  • Fecal occult-blood test (FOBT): The fecal occult-blood test checks for hidden blood in the stool. A newer type of FOBT, known as an immunochemical FOBT, may be more accurate than the standard FOBT.
  • Flexible sigmoidoscopy: A physician uses a lighted tube to look inside the rectum and the lower part of the colon (sigmoid colon) for polyps or areas suspicious for cancer.
  • Colonoscopy: A longer flexible tube is used to view the entire colon.
  • Double-contrast barium enema: A chalky substance called barium is inserted through the rectum and into the colon and rectum. The patient then undergoes x-rays of the colon and rectum so that the physician can evaluate the area for polyps or other abnormalities.

It is recommended that patients with an average risk of colorectal cancer begin colorectal cancer screening at age 50. Screening may consist of FOBT every year and sigmoidoscopy every five years, colonoscopy every 10 years, or double-contrast barium enema every five years. Individuals who are at increased risk of colorectal cancer as a result of family or personal history may need to begin screening at an earlier age or may require more frequent screening.

The Benefits of Screening

A recent study of patients with a first-degree family history of colorectal cancer confirmed that colonoscopy decreases colorectal cancer risk.[1] In a study from the UK , 1678 patients with a first-degree family history of colorectal cancer were classified as either high-risk (from a family with a known genetic predisposition to colorectal cancer) or moderate risk (no known genetic predisposition). All patients received at least one screening colonoscopy. Compared to the number of cancer cases that would be expected among unscreened individuals with a comparable family history, risk of cancer was reduced by 80% in moderate-risk individuals and by 43% in high-risk patients.

The Downside: Inadequate Screening

In spite of the benefit of colonoscopy observed in this and other studies, another recent study reported that many patients are failing to undergo colorectal cancer screening.[2] Researchers evaluated 21,833 patients between the ages of 55 and 70 who were enrolled in a managed care organization in Michigan. During a five-year period (1999 to 2003), the rate of colorectal cancer screening increased slightly, but only 54% of patients received screening that was considered adequate.

Patients who have not yet been screened for colorectal cancer, or who have not met the recommended screening guidelines, may wish to talk with their physician about the screening approach that is best for them.

1) Dove-Edwin I, Sasieni P et al. Prevention of Colorectal Cancer by Colonoscopic Surveillance in Individuals with a Family History of Colorectal Cancer: 16 Year, Prospective, Follow-Up Study. British Medical Journal. Online Publication October 21, 2005.

2) Lafata JE, Williams LK, Ben-Menachem T et al. Colorectal carcinoma screening procedure use among primary care patients. Cancer. 2005;104:1356-61.

Copyright © 2010 CancerConsultants Colon Cancer Information Center. All Rights Reserved.

Tags: Uncategorized

You must be logged-in to the site to post a comment.