Association between index adenomas and advanced neoplasia at third surveillance colonoscopy: Data from the New Hampshire Colonoscopy Registry.

BACKGROUND: Due to a lack of data, the USMTSF does not provide guidance for the 3rd surveillance exam for adenomas detected on index colonoscopy. Our aim was to assess advanced outcome risk at 3rd surveillance in patients with index adenomas. METHODS: We included patients from the New Hampshire Colonoscopy Registry with no genetic syndromes, inflammatory bowel disease, those with first degree relative with CRC < 50 years of age, adequate bowel preparation and no colorectal cancer (CRC) on index, and with three follow-up colonoscopies each >12 months apart. Only patients with normal or low risk findings (1-2 small TAs/SSPs) on 1st and 2nd surveillance exam were included. Individuals were stratified by index adenomas: no adenomas, 1-2 non-advanced adenomas (NAA), 3-4 NAA, 5+NAA and advanced adenomas. A Poisson model adjusting for age, sex, index serrated polyps, endoscopist adenoma detection rates and months to follow up exam (offset variable) predicting advanced neoplasia on 3rd surveillance was performed. RESULTS: Patients (n=1021) with an advanced adenomas on index were found to have a statistically significant increased risk of advanced neoplasia on 3rd surveillance as compared to those patients with no adenomas (adjusted rate ratio=3.96(95%CI:1.96-7.98)). In addition, after adjusting for endoscopists ADRs, the RR was still statistically higher for this group (RR=3.00(95%CI:1.20-7.48)). CONCLUSION: Our data suggest that those with an advanced adenomas on index exam continue to have a statistically significant increased risk of advanced neoplasia on 3rd surveillance. This finding supports close surveillance in patients with these lesions.