Adenoma detection rate influences the risk of metachronous advanced colorectal neoplasia in low-risk patients.

BACKGROUND AND AIMS

In individuals with either no or 1 to 2 nonadvanced adenomas, future risks of advanced colorectal neoplasia (AN) vary according to clinical risk factors. However, little is known about the association between the adenoma detection rate (ADR) and the risk for metachronous AN in patients with low-risk adenomas.

METHODS

We identified 7171 participants with no or 1 to 2 nonadvanced adenomas at first-time screening colonoscopy. The risk of metachronous AN was investigated at surveillance colonoscopy, according to clinical characteristics and the ADR.

RESULTS

In multivariate analysis the risk for metachronous AN was strongly associated with increasing age, male sex, increasing number of adenomas, and the ADR of the endoscopist. With the ADR modeled as a continuous variable, each 1.0% increase in the rate of ADR predicted a 3.0% decrease in the risk of metachronous AN (adjusted odds ratio [OR], .97; 95% confidence interval [CI], .95-.99). With the ADR modeled using a binary cut-off (32%), the risk of metachronous AN was reduced in patients of endoscopists with an ADR ≥32% (adjusted OR, .53; 95% CI, .35-.83). Moreover, the risk of metachronous AN was reduced (adjusted OR, .66; 95% CI, .46-.95) in patients of endoscopists with an ADR in the highest tertile, compared with patients of endoscopists with ADRs in the lowest tertile. The impact of ADR on metachronous AN was significant for patients with low-risk adenomas rather than patients with no adenoma.

CONCLUSIONS

In patients with low-risk adenomas, the ADR of the endoscopist was inversely associated with the risk of metachronous AN.