Sessile Serrated Lesions, Unspecified Serrated Polyps, and Colorectal Cancer Risk
Douglas K. Rex, MD, MASGE, reviewing Li D, et al. Gut 2021 Aug 11.
This study examined the risk of colorectal cancer (CRC) associated with serrated polyp subtypes in patients undergoing their first colonoscopy between 2006 and 2016. There were 695 persons who later developed CRC and 3475 controls. Two expert pathologists reviewed all serrated lesions to characterize them as sessile serrated lesions (SSLs), unspecified serrated polyps (USPs), hyperplastic polyps (HPs), or traditional serrated adenomas (TSAs). A USP is a lesion that has equivocal changes that do not allow for a diagnosis of SSL.
The kappa statistics for SSL and HP diagnosis by the 2 pathologists were 0.9 and 0.74, respectively.
Among all cases combined, the serrated polyp subtypes included 22% SSLs, 51% HPs, 27% USPs, and <1% TSAs. There were no unequivocal large proximal HPs.
The table below shows the adjusted odds ratios (aORs) for CRC at follow-up.
aOR (compared to no polyp)
SSL without dysplasia 3.3
SSL with dysplasia 10.3
Proximal large SSL 12.8
SSL plus adenoma 4.4
HP alone 0.8
USP alone 1.8
USP plus adenoma 2.6
Conventional adenoma 2.2
Advanced adenoma 3.1
In both SSLs and USPs, the risk was almost entirely associated with proximal lesions, not distal lesions.
The CRC risk with SSLs alone was more than twice as high in women as in men.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
Li D, Doherty AR, Raju M, et al. Risk stratification for colorectal cancer in individuals with subtypes of serrated polyps. Gut 2021 Aug 11. (Epub ahead of print) (https://doi.org/10.1136/gutjnl-2021-324301)