Clinicopathological Correlates of Dysplastic Sessile Serrated Lesion: A Prospective Cohort Study With a High Detection Rate.

Background and Aims: Sessile serrated lesions (SSLs) develop colorectal cancer (CRC), through a critical intermediary stage of SSL with dysplasia (SSLd). In this prospective observational study, we aimed to assess clinicopathological correlates of SSLd in the setting of a high lesion-detection rate. Methods: Patients diagnosed with SSL and SSLd from February 2018 until January 2020 were prospectively recruited, and SSLd specimens were re-evaluated by 2 expert pathologists in a blinded manner. Associations were analyzed using multivariate logistic regression models. Results: A total of 6425 patients underwent 7423 colonoscopies, and 2671 SSLs were resected from 1047 patients. The overall SSL detection rate per colonoscopy was 15.9%. The median age of patients with SSL was 54 years (interquartile range, 39-66), and 43.3% were male. After pathologist review, 24 SSLds were confirmed in 20 patients. The median size of SSLd was 8 mm (interquartile range, 5.75-15.25), and 13 of 24 SSLds were <10 mm in size. After multivariate analysis, older age (odds ratio = 1.07, 95% confidence interval = 1.03-1.1) and higher number of synchronous SSLs (odds ratio = 1.12, 95% confidence interval = 1.02-1.23) were associated with the presence of dysplasia. Patient sex and number and size of synchronous adenomas were not associated with the presence of SSLd. Seven of 20 patients with SSLd had synchronous or metachronous SSLd. Six of 20 patients with SSLd met the diagnostic criteria for serrated polyposis syndrome. Conclusion: The overall SSL detection rate was 15.9%, and 0.9% of SSLs were dysplastic. Older age and higher number of synchronous SSL were risk factors for the presence of dysplasia in SSLs. Thirty percent of patients with SSLd had serrated polyposis syndrome, and 35% had multiple SSLd.