Bethesda, MD (Sept. 17, 2008) – Death from colorectal cancer is highly preventable with effective screening and early detection. Many screening options are available, each with advantages and disadvantages, but half of eligible patients still do not participate in colorectal cancer screening. For that reason, a goal of the American Gastroenterological Association (AGA) Institute is to increase colorectal cancer screening rates and improve public health.
The AGA Institute considers colonoscopy the definitive test for colorectal cancer screening and prevention. Colonoscopy is the only test that can both detect cancer at an early curable stage and prevent cancer by removing pre-cancerous polyps. Data published in the Sept. 18, 2008, issue of the New England Journal of Medicine i suggests that computed tomographic (CT) colonography may be another acceptable technology for colorectal cancer screening.
The availability of CT colonography could increase screening rates in eligible patients (i.e. asymptomatic patients over the age of 50) who have not participated in other colorectal cancer screening procedures. However, a number of important questions need to be addressed:
Patients also need to understand that for most people colorectal cancer screening is not a one-time event and that interval examinations are recommended. According to a study by Thomas F. Imperiale et al. ii , published in the same issue of NEJM, a screening interval of five years or longer is appropriate in patients with a normal colonoscopic exam. Because small (< 5 mm) polyps are not typically reported on CT colonography, a negative exam on CT may not be equivalent to a negative colonoscopy. The optimal interval between CT colonography examinations has yet to be defined.
Guided by the principle that gastroenterologists are ideally suited to manage patients with gastrointestinal disorders and that they should be able to utilize any technology that can enable them to provide better patient care, the AGA Institute has taken a leadership role with technologies such as CT colonography. With the best interest of patients in mind, the AGA has monitored this technology, created training standards and will continue to educate those gastroenterologists who wish to provide this procedure to patients.
More information about the AGA Institute's work related to CT colonography reimbursement, training and standards can be found at www.gastro.org/ctc .
Resources for patients on CT colonography, colonoscopy and colorectal cancer can be found at www.gastro.org/patient .
About the AGA Institute
The American Gastroenterological Association (AGA) is dedicated to the mission of advancing the science and practice of gastroenterology. Founded in 1897, the AGA is one of the oldest medical-specialty societies in the U.S. Comprised of two non-profit organizations – the AGA and the AGA Institute – our more than 17,000 members include physicians and scientists who research, diagnose and treat disorders of the gastrointestinal tract and liver. For more information, please visit www.gastro.org .
i Johnson, CD et al. Accuracy of CT Colonography for Detection of Large Adenomas and Cancers. N Engl J Med . 2008;359:1207-1217.
ii Imperiale TF et al. Five-Year Risk of Colorectal Neoplasia after Negative Screening Colonoscopy. N Engl J. Med . 2008;359:1218.
New England Journal of Medicine