Background: Predicting the risk of advanced colorectal neoplasia on the second surveillance colonoscopy could help tailor surveillance.
Objective: To derive and validate a risk index for advanced neoplasia on the second surveillance colonoscopy.
Design: Retrospective cohort.
Setting: Single-specialty practice; Veterans Affairs Medical Center.
Patients: A total of 965 patients with baseline adenomatous polyps, 2 surveillance colonoscopies, and no reported family history of colorectal cancer; validation cohort of 372.
Interventions: Multivariable logistic regression including demographics and previous colonoscopy results; derivation and validation of a risk index.
Main outcome measurements: Advanced adenoma (≥1 cm in size, villous histology, or high-grade dysplasia) on the second surveillance colonoscopy.
Results: Mean age was 57.8 ± 9.8 years, 62% were men, and 36% had an advanced adenoma on the index colonoscopy. Associated with advanced adenoma on the second surveillance colonoscopy were age at index colonoscopy (scored 0 for younger than 55 years of age, 1 for 55-59 years of age, 2 for 60-64 years of age, and 3 for older than 65 years of age) and previous findings (non-neoplastic, nonadvanced, advanced [scored 0, 1, and 2, respectively]) on index colonoscopy and the first surveillance colonoscopy, with scores ranging from 1 to 7. Risks of advanced adenoma on the second surveillance colonoscopy with scores of 5 or less and more than 5 were 4.8% (95% confidence interval, 3.5%-6.4%) and 14.9% (95% confidence interval, 7.4%-25.7%), respectively, comprising 93% and 7%, respectively, of the cohort. Corresponding results in the validation cohort were 5.6% and 19.2%, respectively, comprising 86.1% and 13.9%, respectively, of the cohort.
Limitations: Retrospective study with potential for selection bias.
Conclusion: This index stratifies the risk of advanced adenoma on the second surveillance colonoscopy. If validated independently, it may be useful for tailoring surveillance.
Published by Mosby, Inc.