RESUMEN
BACKGROUND : Endoscopic submucosal dissection (ESD) in colorectal lesions is technically demanding and a significant rate of noncurative procedures is expected. We aimed to assess the rate of residual lesions after a noncurative ESD for colorectal cancer (CRC) and to establish predictive scores to be applied in the clinical setting. METHODS : Retrospective multicenter analysis of consecutive colorectal ESDs. Patients with noncurative ESDs performed for the treatment of CRC lesions submitted to complementary surgery or with at least one follow-up endoscopy were included. RESULTS : From 2255 colorectal ESDs, 381 (17â%) were noncurative, and 135 of these were performed in CRC lesions. A residual lesion was observed in 24 patients (18â%). Surgery was performed in 96 patients and 76 (79â%) had no residual lesion in the colorectal wall or in the lymph nodes. The residual lesion rate for sm1 cancers was 0â%, and for >âsm1 cancers was also 0â% if no other risk factors were present. Independent risk factors for lymph node metastasis were poor differentiation and lymphatic permeation (NC-Lymph score). Risk factors for the presence of a residual lesion in the wall were piecemeal resection, poor differentiation, and positive/indeterminate vertical margin (NC-Wall score). CONCLUSIONS : Lymphatic permeation or poor differentiation warrant surgery owing to their high risk of lymph node metastasis, mainly in >âsm1 cancers. In the remaining cases, en bloc and R0 resections resulted in a low risk of residual lesions in the wall. Our scores can be a useful tool for the management of patients who undergo noncurative colorectal ESDs.