Abstract
Background Serrated polyps have been recognized as precursors of colorectal cancer (CRC) via
the serrated pathway. Endoscopic detection and histopathological evaluation of serrated
polyps are challenging. The aims of this study were to determine detection rates of
the recently proposed entity of clinically relevant serrated polyps (crSPs) and to
identify factors that influence their detection in a primary colonoscopy screening
cohort.
Methods We retrospectively analyzed average-risk screening colonoscopies performed at a tertiary
academic hospital and six community-based private practices in Germany between 01/01/2012
and 14/12/2016. Exclusion criteria were age < 50 years, conditions with increased
risk for CRC (e. g. inflammatory bowel disease, history of CRC, hereditary cancer
syndromes), and incomplete procedures. CrSPs were defined as serrated polyps ≥ 10 mm
and/or > 5 mm located proximally to the splenic flexure. Conventional adenomas were
defined as adenomas excluding serrated polyps.
Results A total of 4161 colonoscopies from average-risk individuals were included (median
age 62 years [interquartile range 56 – 69]; 48.6 % male). CrSPs were detected in 6.9 %,
with a mean detection rate of 4.7 % (95 % confidence interval 2.3 % – 7.2 %). Detection
rates ranged from 0 % to 16.2 %. In multivariate analysis, simultaneous detection
of conventional adenomas and an endoscopist adenoma detection rate of ≥ 25 % were
significantly associated with increased detection of crSPs, with odds ratios of 1.43
(95 %CI 1.11 – 1.85; P = 0.01) and 7.35 (95 %CI 4.43 – 12.19; P < 0.001). The individual endoscopist’s detection rate for conventional adenomas and
crSPs were significantly correlated (r = 0.54, P = 0.02).
Conclusion Detection rates for crSPs differed between participating endoscopists. However, individual
skills to detect polypoid lesions have a relevant bearing on the detection rate of
crSPs.
