Endoscopic Approach to Large Non-pedunculated Colorectal Polyps

Large non-pedunculated colorectal polyps ≥20 mm (LNPCPs) constitute approximately 1% of all colorectal polyps and present a spectrum of risks, including overt and covert submucosal invasive cancer (T1 colorectal cancer (CRC)). Importantly, a curative resection may be achieved for LNPCPs with superficial T1 CRC (T1a or T1b <1000 µm into submucosa), if an enbloc R0 excision (clear margins) with favourable histology is achieved (ie, absence of high-grade tumour budding, lympho-vascular invasion, and poor differentiation). Thus, while consensus recommendations advocate for endoscopic resection as the primary treatment option for LNPCPs, thorough optical assessment is imperative for selecting the most suitable ER strategy. In this review, we highlight the critical components of optical evaluation that assist in predicting the risk of T1 CRC, including morphology (Paris and LST classifications), surface pit/vascular pattern (JNET and Kudo classifications), and lesion location. Different resection modalities, including endoscopic submucosal dissection and endoscopic mucosal resection are discussed, along with important considerations that may influence the resection strategy of choice, such as access to the LNPCP and submucosal fibrosis.