Clinicopathological features of advanced colorectal serrated lesions: A single-center study in China

OBJECTIVE A growing body of evidence indicates that patients with colorectal serrated lesions, especially advanced serrated lesions (ASLs), are at risk of subsequent malignancy. This study aimed to analyze the clinicopathological features of ASLs and the association between ASLs and synchronous advanced colorectal neoplasia (sACN) in a single center of China. METHODS A retrospective cross-sectional study of consecutive symptomatic patients and healthy individuals who underwent colonoscopy between January 2010 and March 2016 was performed. Clinicopathological characteritics of the patients with ASLs were documented from the colonoscopy database. RESULTS Colorectal serrated lesions were pathologically confirmed in 277 (N = 38 981, 0.7%) cases. Among them, 156 (56.3%) were found to have ASLs, with a total of 161 lesions including 71 sessile serrated adenoma/polyps (SSA/P) and 90 traditional serrated adenomas (TSAs). There were no differences in age and gender between the ASL and non-ASL patients. Among the 161 ASLs, 29 (18.0%) were ≥10 mm in diameter. Compared with non-ASLs, ASLs appeared more in the proximal colon (P = 0.007). Flat and subpedunculated lesions were more commonly found in the ASL group compared with the non-ASL group. Nearly all ASLs (160/161) had dysplasia. Moreover, 16 sACN lesions were found in 156 ASL patients, and large diameter (≥10 mm) might be a significant risk factor for sACN (odds ratio 4.35, 95% confidence interval 1.467-12.894, P < 0.05). CONCLUSIONS ASLs are more likely to occur in the proximal colon, and mainly present as flat and sub-pedunculated types. Large ASLs are significantly associated with sACN.