Study on the Association Between Serrated Polyps and Metachronous Advanced Colorectal Neoplastic Lesions

Inclusion Criteria: * Adult patients aged \> 18 years;At least one SP detected during the index colonoscopy and pathologically confirmed as TSA or SSL (according to the 2019 WHO classification criteria);Underwent complete polypectomy during the index colonoscopy;Received regular follow-up at Changhai Hospital, with an interval of ≥ 6 months between the index and follow-up colonoscopies;Complete clinical and pathological data. Exclusion Criteria: * Incomplete colonoscopy or failed cecal intubation;Inadequate bowel preparation, defined as a Boston Bowel Preparation Scale (BBPS) score \< 6 or a score \< 2 in any bowel segment;Withdrawal time \< 6 minutes;Diagnosis of hereditary cancer syndromes, such as familial adenomatous polyposis (FAP) or Lynch syndrome;Concurrent inflammatory bowel disease (IBD) or indeterminate colitis;History of colorectal cancer or other malignancies;Incomplete clinical or pathological records.