The primary aim of this study is to determine the rate of total metachronous advanced neoplasia (TMAN) detection after index detection of serrated lesions (SL) \[sessile serrated polyps (SSPs), traditional serrated adenomas (TSAs)\], and metachronous high-risk adenoma (HRA) after index detection of high-grade dysplasia (HGD).
We will use the database of patients diagnosed with SL or HGD at index colonoscopy with a delay in surveillance and determine the risk of advanced lesions (especially high-risk lesion and CRC detection) of these delayed colonoscopies. The aim is to determine the effects of breach of continuity of care in these patients.
Patients 45-80 who underwent colonoscopy from 2009 to 2022 at the Montreal University Hospital Center (CHUM) with 1+ SL or HGD detected at index colonoscopy and lacking follow-up within or beyond the surveillance interval recommended by 2020 USMSTF guidelines.
1) Patients with a diagnosis of inflammatory bowel disease;
2) Hereditary CRC syndromes;
3) CRC at index colonoscopy;
4) Serrated polyposis syndrome;