Colonoscopy Found To Be Most Effective Colorectal Cancer Screening Method, Though Alternative Methods Show Promise

Researchers compared the sensitivity of standard colonoscopy to CT colonography (often referred to as “virtual colonoscopy”) and air contrast barium enema in patients with increased risk of developing colorectal cancer. They found that the sensitivity of standard colonoscopy was substantially better than both CT colonography and barium enema. Despite the findings of this study, the American Gastroenterological Association (AGA) encourages future comparative studies of these methods in populations with average risk for developing CRC because these individuals constitute a majority of those being screened for colorectal cancer.

“This study demonstrates that colonoscopy is still the most accurate test for the detection of polyps and small cancers, and also allows their removal by endoscopic techniques,” says AGA President Emmet B. Keeffe, MD. “However, no colorectal cancer screening test is perfect and we encourage people to speak with their physicians to determine which test best fits their needs and risk level. The best screening test is the one that gets done.”

Guidelines of multiple agencies and professional societies underscore the importance of screening for all individuals 50 years of age and older. Currently, there are several tests that may be used to screen for colorectal cancer, the second-leading cause of cancer deaths in the United States. Approved tests include colonoscopy, flexible sigmoidoscopy, fecal occult blood test and barium enema. Each screening option has advantages and disadvantages.

The AGA recently assembled a task force to undertake a critical analysis of available information on the capabilities of CT colonography and to consider its potential role in colorectal cancer screening. Results of studies of CT colonography for colorectal cancer screening have been variable, leading the task force to conclude that standard colonoscopy should continue to be the procedure of choice for detecting colon polyps and cancer. However, CT colongraphy is rapidly evolving and has significant promise as a screening option. Conclusions of the task force were published in the September issue of the journal Gastroenterology.

Citation: Van Dam J, Cotton P, Johnson CD, McFarland B, Pineau BC, Provenzale D, Ransohoff D, et al. AGA Future Trends Report: CT Colonography. Gastroenterology 2004: 127(3): 970-986

About the AGA

The American Gastroenterological Association (AGA) is dedicated to the mission of advancing the science and practice of gastroenterology. Founded in 1897, the AGA is the oldest medical-specialty society in the United States. The AGA’s 14,000 members include physicians and scientists who research, diagnose and treat disorders of the gastrointestinal tract and liver. On a monthly basis, the AGA publishes two highly respected journals, Gastroenterology and Clinical Gastroenterology and Hepatology. The AGA’s annual meeting is Digestive Disease Week, which is held each May and is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.

*In the study published in The Lancet, sensitivity is the proportion of individuals that were correctly identified as having a colonic polyp or cancer.