The Extent to Which Colonoscopy Saves Lives Has Been Established

Colonoscopy was known, in colon and rectal cancer, to enable early diagnosis and substantially reduce mortality from these cancers. Results of a new study, the largest case-control study on the subject, also show colonoscopy and "how much" it reduces large bowel cancer mortality.

Many doctors agree that colonoscopy is often lifesaving. In the United States alone, approximately 14 million people are estimated to undergo it annually. As a cancer screening method, its use among patients in the United States was, in 2001, 8%, while after 2007 it exceeded 32%.

• What is colonoscopy? Why and how is it performed?

Note: For early detection of large bowel cancer, screening colonoscopy is recommended for both women and men starting at 50, every 10 years.

Questions also remain about whether colonoscopy is more effective than other colorectal screening tests, such as stool tests.

From a broader healthcare perspective, the issue is not only comparative effectiveness: costs, cost-effectiveness, resource availability and allocation must also be considered.

• 7 alternatives to colonoscopy for early detection of colon and rectal cancer

Four randomized controlled studies comparing colonoscopy-based screening with methods detecting large bowel cancer biomarkers in stool are ongoing.

Details of the Study Discussed

Between 1 January 2002 and 31 December 2008, the study identified 4964 patients who had experienced colorectal cancer. Approximately 4 times as many healthy people (19856) served as controls. Participants' median age was 71.7.

Study Results:

• Cancer patients had undergone colonoscopy less often than controls (13.5% versus 26.4%).
• The median time between colonoscopy and cancer diagnosis in patients was 43.5 months.
• Most importantly, colonoscopy reduced mortality from left-sided colon cancer by 72% and right-sided colon cancer by 46%.

A Significant Risk Reduction

These data again show colonoscopy's importance in reducing large bowel cancer risk. Researchers also emphasize a high rate of adenoma (polyp) detection as defining the importance of a high-quality endoscopist.

Another United States study showed that each 1% increase in adenoma detection was associated with a 3% decrease in colorectal cancer incidence.

In conclusion, as colonoscopy screening becomes more widespread, both colorectal cancer incidence, one of the most common cancers, and associated mortality decline.