Published research suggests that colonoscopy saves lives through detection and removal of adenomas, or benign tumors. Patients who have adenomas removed during colonoscopy are at higher risk for recurring adenomas and colorectal cancer than those who have had a negative colonoscopy.

Studies to determine patient risk factors for recurring adenomas and colorectal cancer have focused on characteristics of the adenoma, but characteristics of the colonoscopy had not been considered.

Researchers used data from a previously published population-based screening study of 3,148 patients with colorectal cancer and 3,274 control participants to determine the role of both colonoscopy and polyp characteristics in the risk for colorectal cancer.

The authors identified 155 case participants and 260 control participants who had a physician-validated colonoscopy with detection of polyps within the past 10 years. The researchers found that colonoscopy-related factors, such as lack of complete removal of all polyps and lack of surveillance colonoscopy within five years, was a more important indicator of future colorectal cancer than polyp characteristics.

Overall, two in five cancer cases could be attributed to the presence of one or more of the colonoscopy-related factors, whereas one in five cancer cases were attributable to the presence of one or more high-risk polyps.

The researchers conclude that these findings emphasize the importance of optimizing procedural aspects of colonoscopy.