S335 Sessile Serrated Polyps - More Prevalent Than Previously Thought

Abstract

Introduction: Sessile serrated polyps (SSP) are precursors of up to 30% of colorectal cancers. There are significant differences in the documented prevalence of SSPs in the literature, ranging from 3-10%. We aimed to clarify the prevalence of SSPs by gender, ethnicity, age, and obesity in a large academic medical center in Southern California. Methods: Data was analyzed retrospectively, including all screening and surveillance colonoscopies performed at our tertiary outpatient facility from 2012 to 2019. We evaluated gastroenterologists who performed at least 200 colonoscopies and included all patients over the age of 40. Statistical analysis was performed using chi-square and two-sample t-test. Results: Among 4,430 colonoscopies evaluated, 2,269 (51.2%) were in females. 495 of the procedures had at least one SSPs detected (11.2%). whites had higher SSP detection rates (SDR) compared to non-white ethnicities (13% vs 8%, p< 0.01). There were no differences in SDR based on gender (P=0.10), advanced age >70 (P=0.65) or obesity (P=0.54). Compared with adenomas, SSPs were generally larger with an average size of 7.4mm compared to 4.1mm (p< 0.01) and had a higher percentage of polyps >9mm (21.8% vs 7.2%, p< 0.01). SSPs were also more likely to be found in the proximal colon compared to adenomas (75.9% vs 63.8%, p< 0.01). Conclusion: Our study shows a higher prevalence of SSPs detected during colonoscopy than previously established, especially in whites. Our data confirms previous studies which showed that SSPs tend to be right sided and larger than adenomas. However, this size difference may reflect a larger miss rate for small SSPs, which tend to be flat and difficult to find. While SSPs are not as commonly detected as adenomas, they play a significant role in the development of colorectal cancer, especially interval cancers. As such, endoscopists should be rigorous in their evaluation to recognize all sessile serrated lesions.