Interval colorectal cancer after colonoscopy.

BACKGROUND

As more patients are screened for colorectal cancer a small but significant number of interval cancers develop after colonoscopy for colorectal cancer screening.

MATERIALS AND

METHODS

We reviewed records of 75,314 adult patients who underwent colonoscopy for screening or diagnostic purposes between 1998 and 2006 inclusively, and identified 77 who developed interval cancers within the next 5 years. We reviewed their original endoscopic findings to determine the clinical and endoscopic factors that might predict a greater risk for future cancers.

RESULTS

Patients aged ≥ 60 years had a higher risk of an interval neoplasm (P < .0001). Interval cancers were more common on the right side of the colon and in the hepatic flexure (both P < .0001). We did not observe an increased rate of interval cancers in patients with poor preparation (P = .799); however, examination completion rates did affect the rate of interval cancers (P = .016).

CONCLUSION

Better identification of higher risk patients and assurance of follow-up examinations might increase the percentage of colon cancers discovered at an early stage. Special attention to careful examination of the right colon is key.