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Colorectal cancers soon after colonoscopy: a pooled multicohort analysis.
Douglas J Robertson1, David A Lieberman, Sidney J Winawer
1Department of Veterans Affairs Medical Center, White River Junction, VT and Dartmouth Medical School & The Dartmouth Institute, , Hanover, New Hampshire, USA.
Gut
|June 25, 2013
Summary
Colorectal cancer (CRC) can still be diagnosed after a colonoscopy. Most interval cancers are due to missed or incompletely removed polyps, highlighting the need for thorough colonoscopy.
Area of Science:
- Gastroenterology
- Oncology
- Preventive Medicine
Background:
- Colorectal cancer (CRC) diagnosis can occur despite recent colonoscopies.
- Individuals undergoing surveillance for colonic adenomas are at risk for interval cancers.
Purpose of the Study:
- To investigate the reasons for CRC diagnosis after a colonoscopy with complete polyp removal.
- To identify factors contributing to interval colorectal cancer diagnoses.
Main Methods:
- Pooled data from eight North American studies involving patients with adenomas.
- Utilized an algorithm to classify interval cancers based on time, adenoma characteristics, and detection methods.
- Assigned interval cancers to categories: new, missed, incompletely resected, or failed biopsy detection.
Main Results:
- 58 of 9167 participants (0.6%) were diagnosed with invasive CRC during follow-up.
- Most interval cancers (52%) were classified as probable missed lesions.
- 19% of cancers were possibly related to incomplete resection of prior non-invasive lesions.
- 16% of diagnosed cancers resulted in death from CRC.
Conclusions:
- Colorectal cancer is occasionally diagnosed despite colonoscopy with polyp removal intent.
- Missed lesions and incomplete polyp resection are primary contributors to interval CRC.
- Emphasizing thorough lesion identification and complete removal during colonoscopy may reduce interval cancers.
