Optimal extent of lymphadenectomy improves prognosis and guides adjuvant chemotherapy in esophageal cancer: A propensity score-matched analysis

BACKGROUND The optimal extent of lymphadenectomy in esophageal squamous cell carcinoma (ESCC) patients remained debatable. AIM To explore the ideal number of cleared lymph nodes in ESCC patients undergoing upfront surgery. METHODS In this retrospective, propensity score-matched study, we included 1042 ESCC patients who underwent esophagectomy from November 2008 and October 2019. Patients who underwent neoadjuvant therapy were excluded. We collected patients' clinicopathological features and information regarding lymph nodes, including the total number of resected lymph nodes (NRLN), and pathologically diagnosed positive lymph nodes (RPLN). SPSS and R software were used for statistical analysis. RESULTS Among the included 1042 patients, two cohorts: <= 21 (n = 664) and > 21 NRLN (n = 378) were identified. The final prognostic model included four variables: T stage, N, venous thrombus, and the number of removed lymph nodes. Among them, NRLN > 21 was determined as an independent prognosticator after surgery for esophageal cancer (hazards regression = 0.66, 95% confidence interval: 0.50-0.87, P = 0.004). A nomogram was created based on the regression coefficients of the variables in the final model. In the training cohort, the predictive model displayed an uncorrected five-year overall survival C-index of 0.659, with a bootstrap-corrected C-index of 0.654. In the subgroup analysis, adjuvant chemotherapy was beneficial in the subgroup with NRLN > 21 and RPLN <= 0.16 and NRLN <= 21 and RPLN > 0.16. CONCLUSION NRLN > 21 was an independent prognostic factor after ESCC surgery. The combination of NRLN and RPLN may provide a reference for adjuvant chemotherapy use in potential beneficiaries.