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 lymphadenec-tomy. Summary of 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 2306 patients, the second (4–8 nodes), seventh (21–24 nodes) and eighth decile (25–30 nodes) of lymphadenectomy showed the lowest all-cause 5-year mortality compared to the first decile [hazard ratio (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% CI0.40–0.78), 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.