Resection of the irradiated esophagus: the impact of lymph node yield on survival

There is debate surrounding the appropriate threshold for lymph node harvest during esophagectomy in patients with esophageal cancer, specifically for those receiving preoperative radiation. The purpose of this study was to determine the impact of lymph node yield on survival in patients receiving preoperative chemoradiation for esophageal cancer. The National Cancer Database (NCDB) was utilized to identify patients with esophageal cancer that received preoperative radiation. The cohort was divided into patients undergoing minimal (<9) or extensive (≥9) lymph node yield. Demographic, operative, and postoperative outcomes were compared between the groups. Kaplan-Meier analysis with the log rank test was used to compare survival between the yield groups. Cox proportional hazards model was used to determine the association between lymph node yield and survival. In total, 886 cases were included: 349 (39%) belonging to the minimal node group and 537 (61%) to the extensive group. Unadjusted 5-year survival was similar between the minimal and extensive groups, respectively (37.3% vs. 38.8%; P > 0.05). After adjustment using Cox regression, extensive lymph node yield was associated with survival (hazard ratio 0.80, confidence interval 0.66-0.98, P = 0.03). This study suggests that extensive lymph node yield is advantageous for patients with esophageal cancer undergoing esophagectomy following induction therapy. This most likely reflects improved diagnosis and staging with extensive yield.