Is Additional Surgery Necessary After Non-Curative Endoscopic Submucosal Dissection for Early Colorectal Cancer?

Background: Although endoscopic submucosal dissection (ESD) is considered to be a curative treatment for early colorectal cancer, additional surgery with lymph node dissection is routinely recommended for patients treated in non-curative ESD, owing to the risk of residual cancer and lymph node metastasis (LNM). However, in clinical practice, few patients are found to have either residual cancer or LNM after additional surgery. Therefore, we conducted this study to determine the risk factors associated with residual cancer and LNM. Methods: Patients with early colorectal cancer after non-curative ESD and additional surgery from January 2015 to May 2019 were retrospectively identified. Clinicopathological characteristics were collected to determine the predictors of residual cancer and LNM. Results: A total of 62 patients were enrolled for analysis in this study. After additional surgery, residual cancer and LNM was detected in 12 patients (19.35%). Clinicopathological comparison of patients with the presence or absence of residual cancer and LNM demonstrated that piecemeal resection (80% vs. 14.04%, P < 0.001), submucosal invasion greater than 2000 mu m (26.09% vs. 0%, P = 0.026), lymphovascular infiltration (37.5% vs. 13.04%, P = 0.033), and perineuronal invasion (75% vs. 15.52%, P = 0.004) were more frequent in residual cancer and LNM cases. Multivariate analysis identified lymphovascular infiltration (P = 0.031) as the only significantly independent risk factor associated with residual cancer and LNM. Conclusions: Additional surgery with lymphadenectomy should be performed after non-curative ESD owing to the high risk of residual cancer and LNM, especially in cases with lymphovascular infiltration.