Association of distal hyperplastic polyps and proximal neoplastic lesions: a prospective study of 5613 subjects

Abstract

Current evidence of whether distal hyperplastic polyps (HPs) are markers of proximal neoplasia (PN) is mixed. We evaluated the association between distal neoplasia and synchronous PN in asymptomatic subjects. We recruited 5819 Chinese asymptomatic screening participants 50 to 70 years of age who underwent colonoscopy in Hong Kong from 2008 to 2014, of whom 206 subjects with distal advanced neoplasia or cancer were excluded. The association between distal pathology (tubular adenomas [TAs], HPs, no polyps) and proximal pathology (PN, proximal advanced neoplasia [PAN]) was assessed by multivariate regression models, overall and stratified by the Asia Pacific Colorectal Screening scoring system (scores of 4-7, high risk; scores of 0-3, lower risk). The prevalence of PN in the no distal polyps group, distal HPs group, and distal TAs group was 14.8%, 19.3%, and 29.4%, respectively. The corresponding prevalence of PAN was 1.8%, 3.2%, and 3.5%. Participants with distal HPs did not have significantly higher odds of PN (adjusted odds ratio [AOR] 1.24; 95% confidence interval [CI], 0.97-1.59; P = .089), and their association with PAN was marginally significant (AOR 1.77; 95% CI, 1.00-3.13; P = .052), except in lower risk subjects for whom the odds of PAN were marginally higher in the distal HPs group than the no distal polyps group (AOR 1.97; 95% CI, 1.01-3.85; P = .048). Overall, the distal polyps group had significantly lower odds of PN than the distal TAs group (AOR 0.55; 95% CI, 0.40-0.76; P < .001). The increased risk of PN and PAN among those with distal HPs was modest. A direct association between distal HPs and PN is lacking, and this implies a need for a multivariate assessment of the risk of PAN. Recommending colonoscopy for every patient with distal HPs detected by screening sigmoidoscopy is not supported by this study.