S. Mahoney1, P. Strassle2, M. Meyers1 1University Of North Carolina At Chapel Hill,Dept Of Surgery,Chapel Hill, NC, USA 2University Of North Carolina At Chapel Hill,School Of Public Health, Dept Of Epidemiology,Chapel Hill, NC, USA
Introduction: The impact of lymph node (LN) dissection in esophageal cancer outcomes remains unclear. We sought to examine trends in LN yield over time in patients undergoing curative resection for esophageal cancer and the relationship with survival.
Methods: All National Cancer Database patients >18yo undergoing esophagectomy for adenocarcinoma or squamous cancer from 2004-2015 were included except those with metastatic disease or palliative treatment. Bivariate analyses comparing demographics and cancer characteristics, stratified by LN yield, were compared using Chi-square and Wilcoxon-Mann-Whitney tests. Trends in LN yield over time were assessed using Poisson regression. 5-year survival differences were compared using Kaplan-Meier curves and multivariable Cox proportional hazards regression.
Results: 20,588 patients were included. 71% received neoadjuvant therapy. Most (82%) were adenocarcinoma. Stage II (44%) and stage III (40%) predominated. Average LN yield increased over time from 11.7 to 16.4 (p<0.0001) as did the proportion of patients with 10-19 LN examined (32% to 45%) and >20 LN examined (14% vs. 28%). The average number of positive LN remained the same (1.4 vs. 1.2; p=0.21). Although crude survival was associated with increased LN yield (Table), adjusted survival had no association with LN yield. Similarly, there was no association with survival when LN yield was treated as a linear variable (HR for any 5 LN increase 0.99, 95% CI 0.98, 1.01).
Conclusion: Improvements in LN yield with esophagectomy has been seen on a population level over time. However, higher LN yield is not associated with improvements in adjusted survival in patients with resected esophageal cancer.
