Abstract

BACKGROUND AND AIMS: Among the characteristics of high-risk adenomas (HRA), some may predict a higher risk of metachronous advanced lesions. Our aim was to assess which HRA characteristics are associated with high risk of metachronous colorectal cancer (CRC) or advanced adenomas (AA).METHODS: We systematically searched Pubmed, EMBASE and Cochrane for cohort studies and clinical trials of CRC or AA incidence at surveillance stratified by baseline lesion size, histology, and multiplicity. We calculated pooled relative risks (RR) using a random-effects model. Heterogeneity was assessed with the I2 statistic.RESULTS: Fifty-five studies were included, with 936,540 patients. CRC incidence per 1,000 person-years was 2.6 (2.1-3.0) for adenomas =20mm, 2.7 (2.2-3.2) for high-grade dysplasia (HGD), 2.0 (1.8-2.3) for villous component, 0.8 (0.1-1.4) for =5 adenomas, 1.0 (0.7-1.2) for =3 adenomas. Metachronous CRC risk was higher in adenomas =20mm vs 10-19mm (RR 2.08, 95%CI 1.20-3.61), HGD vs low-grade dysplasia (RR 2.89, 95%CI 1.88-4.44), villous vs tubular (RR 1.75, 95%CI 1.33-2.31). No significant differences in CRC risk were found in =3 adenomas vs 1-2 (RR 1.24, 95%CI 0.84-1.83), nor in =5 adenomas vs 3-4 (RR 0.79, 95%CI 0.30-2.11). Compared to normal colonoscopy, RR for CRC risk was 2.61 (95%CI 2.06-3.32) for =10mm, 6.62 (95%CI 4.60-9.52) for HGD, 3.58 (95%CI 2.24-5.73) for villous component, 2.03 (95%CI 1.40-2.94) for =3 adenomas. Similar trends were seen for metachronous AA.CONCLUSION: Metachronous CRC risk is highest in patients with baseline adenomas with =20mm or HGD. Multiplicity does not seem to be associated with substantially higher CRC risk.

View details for DOI 10.1016/j.cgh.2022.12.005

View details for PubMedID 36549471