Article Text
Abstract
Background Surveillance colonoscopy after polyp removal is recommended to prevent subsequent colorectal cancer (CRC). It is known that advanced adenomas have a substantially higher risk than non-advanced ones, but optimal intervals for surveillance remain unclear.
Design We prospectively followed 156 699 participants who had undergone a colonoscopy from 2007 to 2017 in a large integrated healthcare system. Using multivariable Cox proportional hazards regression we estimated the subsequent risk of CRC and high-risk polyps, respectively, according to index colonoscopy polyps, colonoscopy quality measures, patient characteristics and the use of surveillance colonoscopy.
Results After a median follow-up of 5.3 years, we documented 309 CRC and 3053 high-risk polyp cases. Compared with participants with no polyps at index colonoscopy, those with high-risk adenomas and high-risk serrated polyps had a consistently higher risk of CRC during follow-up, with the highest risk observed at 3 years after polypectomy (multivariable HR 5.44 (95% CI 3.56 to 8.29) and 8.35 (95% CI 4.20 to 16.59), respectively). Recurrence of high-risk polyps showed a similar risk distribution. The use of surveillance colonoscopy was associated with lower risk of CRC, with an HR of 0.61 (95% CI 0.39 to 0.98) among patients with high-risk polyps and 0.57 (95% CI 0.35 to 0.92) among low-risk polyps. Among 1548 patients who had high-risk polyps at both index and surveillance colonoscopies, 65% had their index polyps in the proximal colon and 30% had index and interval polyps in the same segments.
Conclusion Patients with high-risk polyp findings were at higher risk of subsequent CRC and high-risk polyps and may benefit from early surveillance within 3 years. The subsite distribution of the index and recurrent high-risk polyps suggests the contribution of incomplete resection and missed lesions to the development of interval neoplasia.
- colorectal cancer
- surveillance
- colonic polyps
- colonoscopy
Data availability statement
Data are available upon reasonable request.
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Data availability statement
Data are available upon reasonable request.
Footnotes
X @MingyangSong3
Contributors GP: study concept and design, acquisition of data, analysis and interpretation of data, drafting of the manuscript, statistical analysis, obtained funding. M-MH: analysis and interpretation of data, drafting of the manuscript, statistical analysis. MV: technical support, analysis and interpretation of data, drafting of the manuscript, statistical analysis. MDK: technical support, critical revision of the manuscript for important intellectual content. KW: acquisition of data, material support, critical revision of the manuscript for important intellectual content. MS: guarantor, study concept and design, statistical analysis, critical revision of the manuscript for important intellectual content, technical and material support, study supervision, obtained funding.
Funding German Research Foundation (Deutsche Forschungsgemeinschaft (DFG)—Project No 426308975 to GP).
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
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