Factors Affecting Proximal Serrated Polyp Detection Rate During Screening Colonoscopy

Abstract

Introduction: Recently, the serrated polyp-neoplasia pathway has been identified as an alternative to adenoma-carcinoma pathway for the development of sporadic colorectal cancer. It may account for 15-20% of incident colorectal cancers and potentially, majority of the interval cancers. Serrated polyps are frequently flat or sessile, located in the proximal colon and may be overlooked during colonoscopy. In this study, we assessed the factors associated with proximal serrated polyp detection rate (PSPDR) during screening colonoscopy.Table: Table. Factors Affecting Proximal Polyp Detection RateTable: Table. Characteristics of Patients and EndoscopistsMethods: A retrospective review of all screening colonoscopies, in patients ≥50 years of age performed between 2012 and 2014 was done. Patients who had a complete colonoscopy with excellent, good and adequate bowel preparation were included. Serrated polyps included hyperplastic polyps and sessile serrated adenomas. Proximal colon was defined as cecum to splenic flexure. PSPDR according to gender, race (Caucasians vs African Americans), timing of colonoscopy (morning vs afternoon), fellow participation, quality of bowel preparation as per the Aronchick scale (excellent vs. good vs adequate), gender and specialty of the endoscopist (gastroenterologist vs. non-gastroenterologist) was calculated and compared using t-tests. Data are presented as mean ± standard deviation. All analyses were done using SAS (version 9.4, The SAS Institute, Cary, NC) and a P value of <0.05 was considered significant. Results: A total of 4151 patients were included in the analysis. Average patient age was 60.0±7.7 years and 53.2% patients were females. 63.5% physicians were gastroenterologists and 36.5% were nongastroenterologists. Average PSPDR was 6.1±5.5%. Caucasians had significantly higher PSPDR than African Americans (6.6±6.5 vs 3.2±7.4; P<0.05). A trend of higher PSPDR was observed for gastroenterologists as compared to non-gastroenterologists (P=0.09) and female endoscopists as compared to male endoscopists (P=0.05). Timing of the colonoscopy and fellow participation had no impact on PSPDR. A trend for lower PSPDR was noted in patients with excellent bowel preparation as compared to those with good or adequate bowel preparation. Conclusion: Proximal serrated polyps are more prevalent in Caucasians as compared to African Americans. A trend for higher PSPDR was noted for gastroenterologists and female endoscopists. Interestingly, excellent bowel preparation was associated with lower PSPDR, likely from clearing of the overlying mucous cap.