Surveillance of colorectal neoplasia: a review of guidelines, current evidence, and future directions.

About one third of individuals undergoing colonoscopy for colorectal cancer (CRC) screening are found to have neoplasms that require ongoing colonoscopic surveillance for metachronous neoplasia. Current guidelines for post-polypectomy surveillance interval are based on polyp features of size, histology, and multiplicity. Recent large, observational cohort studies delineate CRC risk among individuals with previous neoplasia while others investigate the role of incorporating patient and endoscopist characteristics in addition to polyp features to more precisely identify patients most likely to benefit from surveillance. Several gaps in colorectal neoplasia surveillance remain, including the role of noninvasive stool-based tests and surveillance cessation approaches for older adults. The purpose of this narrative review is to summarize current post-polypectomy surveillance guidelines from around the world, describe recent observational cohort studies quantifying post-polypectomy CRC risk, highlight novel approaches to risk-stratification for surveillance, summarize ongoing clinical trials of surveillance modalities and intervals that will impact practice, and outline an agenda for future research to further improve the efficiency and effectiveness of colorectal neoplasia surveillance.