Correlation between adenoma and serrated lesion detection rates in an unselected outpatient population

Background: Serrated lesions have been recently implicated in colorectal carcinogenesis. Adenoma detection rate has been related with the risk of interval cancer. The correlation between adenoma detection rate and the serrated lesion detection rate is unclear. Aim: To assess the correlation between adenoma- and serrated lesion-detection rate in an unselected setting of outpatient colonoscopies. Methods: Consecutive outpatients were retrospectively evaluated in one centre. Detection rates were expressed as number of patients with at least one serrated lesion or adenoma. For each endoscopist, correlation between adenoma detection rate and serrated lesions detection rate was calculated. Results: Six endoscopists performed 2974 colonoscopies. 3240 lesions (59.5% adenomas, 37.8% serrated lesions, 0.5% cancer, and 2.3% other histology) were detected in 1228 procedures. Median adenoma detection rate and serrated lesions detection rate per endoscopist were 29.3% and 22.4%, respectively. A positive correlation between adenoma and serrated lesion detection rate (r2=0.78, p<0.001) was detected. Conclusions: Our study showed a statistically significant correlation between adenoma detection rate and serrated detection rate.