Postpolypectomy surveillance recommendations are based on observational studies, often using advanced adenomas at follow-up as their primary outcome.
A new meta-analysis focused on the risk of incident cancer and related mortality reviewed 12 studies with 510,019 patients. Colorectal cancer incidence per 10,000 person-years was slightly higher in those with low-risk adenomas (1-2 adenomas <10 mm with tubular histology and only low-grade dysplasia) than no adenomas, with a statistically significant odds ratio (OR) of 1.26 (95% confidence interval [CI], 1.06-1.5). For those with high-risk adenomas compared to those with no adenomas, the odds ratio for cancer was 2.92 (95% CI, 2.31-3.69). Cancer-related mortality in those with low-risk adenomas compared to no adenomas was not statistically significant (OR, 1.15; 95% CI, 0.76-1.74) but was higher in those with high-risk adenomas (OR, 2.69; 95% CI, 1.87-3.87). Both cancer incidence and mortality were also significantly higher in those with high-risk adenomas compared with low-risk adenomas.
The authors argue that these data indicate that surveillance intervals in those with low-risk adenomas should be the same as those with no adenomas.
Duvvuri A, Chandrasekar VT, Srinivasan S, et al. Risk of colorectal cancer and cancer related mortality after detection of low-risk or high-risk adenomas, compared with no adenoma, at index colonoscopy: a systematic review and meta-analysis. Gastroenterology
2021 Jan 28. (Epub ahead of print) (https://doi.org/10.1053/j.gastro.2021.01.214