Extent of Lymphadenectomy and Long-Term Survival in Esophageal Cancer.

Objective To examine the hypothesis that survival in esophageal cancer increases with more removed lymph nodes during esophagectomy up to a plateau, after which it levels out or even decreases with further lymphadenectomy. Summary background data There is uncertainty regarding the ideal extent of lymphadenectomy during esophagectomy to optimize long-term survival in esophageal cancer. Methods This population-based cohort study included almost every patient who underwent esophagectomy for esophageal cancer in Sweden or Finland in 2000-2016 with follow-up through 2019. Degree of lymphadenectomy, divided into deciles, was analyzed in relation to all-cause 5-year mortality. Multivariable Cox regression provided hazard ratios (HR) with 95% confidence intervals (95% CI) adjusted for all established prognostic factors. Results Among 2,306 patients, the 2nd (4-8 nodes), 7th (21-24 nodes) and 8th decile (25-30 nodes) of lymphadenectomy showed the lowest all-cause 5-year mortality compared to the 1st decile (HR = 0.77, 95% CI 0.61-0.97, HR = 0.76, 95% CI 0.59-0.99, and HR = 0.73, 95% CI 0.57-0.93, respectively). In stratified analyses, the survival benefit was greatest in decile 7 for patients with pathological T-stage T3/T4 (HR = 0.56, 95% CI 0.40-0.78), although it was statistically improved in all deciles except decile 10. For patients without neoadjuvant chemotherapy, survival was greatest in decile 7 (HR = 0.60, 95% CI 0.41-0.86), although survival was also statistically significantly improved in deciles 2, 6, and 8. Conclusion Survival in esophageal cancer was not improved by extensive lymphadenectomy, but resection of a moderate number (20-30) of nodes was prognostically beneficial for patients with advanced T-stages (T3/T4) and those not receiving neoadjuvant therapy.