Abstract
This study was performed to evaluate the prognostic effect of lymphadenectomy on outcomes in patients with resectable metastatic colorectal adenocarcinoma (mCRC). We selected patients with mCRC from 2004 to 2013 from Surveillance, Epidemiology, and End Results Program (SEER) database. Kaplan-Meier analysis, univariate Cox regression and multivariate Cox regression analysis were performed to assess the clinical value of lymphadenectomy on overall survival (OS) and cause-specific survival (CSS) of patients with resectable mCRC. A total 24178 eligible patients were included, 23056 (95.36%) of which received lymphadenectomy. Results showed that lymphadenectomy was an independent protective factor for survival of patients with mCRC overall [OS (HR: 0.86, 95%CI: 0.79-0.93, P=0.002) and CSS (HR: 0.85, 95%CI: 0.78-0.93, P<0.001)]. Further analysis showed that lymphadenectomy improved survival of patients with T1 stage [OS (HR: 0.51, 95%CI: 0.39-0.66, P<0.001); CSS (HR: 0.48, 95%CI: 0.36-0.65, P<0.001)], distal [OS (HR: 0.65, 95%CI: 0.56-0.75, P<0.001); CSS (HR: 0.65, 95%CI: 0.65-0.75, P<0.001)], rectal [OS (HR: 0.60, 95%CI: 0.52-0.70, P<0.001); CSS (HR: 0.59, 95%CI: 0.51-0.69, P<0.001)] , well/moderately differentiated [OS (HR: 0.62, 95%CI: 0.56-0.70, P<0.001); CSS (HR: 0.62, 95%CI: 0.55-0.69, P<0.001)], N1 stage [OS (HR: 0.76, 95%CI: 0.67-0.85, P<0.001); CSS (HR: 0.74, 95%CI: 0.65-0.84, P<0.001)] and N2 stage [OS (HR: 0.63, 95%CI: 0.54-0.74, P<0.001; CSS (HR: 0.65, 95%CI: 0.55-0.77, P<0.001)) mCRC. While lymphadenectomy might not improve survival of patients with T4 stage, proximal, poor or undifferentiated, N3 and N4 stage mCRC. In general, Additional lymphadenectomy was suggested for patients with mCRC overall. However, lymphadenectomy might not improve survival of patients with mCRC of higher malignancy tendency, such as T4 stage, proximal location, poor or undifferentiation, N3 and N4 stages.