Adequate Lymphadenectomy as a Quality Measure in Esophageal Cancer: Is there an Association with Treatment Approach?

BACKGROUND: The national comprehensive cancer network defines adequate lymphadenectomy as evaluation of ≥ 15 lymph nodes in esophageal cancer. However, varying thresholds have been suggested following neoadjuvant therapy. OBJECTIVES: Our objectives were to (1) explore trends in adequate lymphadenectomy rates over time; (2) evaluate unadjusted lymphadenectomy yield by treatment characteristics; and (3) identify independent factors associated with adequate lymphadenectomy. METHODS: The National Cancer Data Base was used to identify patients who underwent esophagectomy for cancer from 2004 to 2015. Adequate lymphadenectomy trends over time were evaluated using the Cochrane–Armitage test, and lymph node yield by treatment approach was compared using the Mann–Whitney U and Kruskal–Wallis tests. Associations with treatment factors were assessed by multivariable logistic regression. RESULTS: Among 24,413 patients, 9919 (40.6%) had adequate lymphadenectomy. Meeting the nodal threshold increased over time (52.6% in 2015 vs. 26.0% in 2004; p < 0.01). Lymph node yield did not differ based on neoadjuvant therapy (median 12 [interquartile range 7–19] with and without neoadjuvant therapy; p = 0.44). Adequate lymphadenectomy was not associated with neoadjuvant therapy (40.5% vs. 40.8%, odds ratio [OR] 0.94, 95% confidence interval [CI] 0.82–1.07), but was associated with surgical approach (52.7% of laparoscopic cases, OR 1.28, 95% CI 1.06–1.56; 61.2% of robotic cases, OR 1.71, 95% CI 1.34–2.19, vs. 43.5% of open cases), and increasing annual esophagectomy volume (55.6% in the fourth quartile vs. 32.6% in the first quartile; OR 3.57, 95% CI 2.35–5.43). CONCLUSIONS: Despite increases over time, only 50% of patients undergo adequate lymphadenectomy during esophageal cancer resection. Adequate lymphadenectomy was not associated with neoadjuvant therapy. Focusing on surgical approach and esophagectomy volume may further improve adequate lymphadenectomy rates.