Factors influencing quality of lymphadenectomy in minimally invasive esophagectomy: a US-based analysis

NCCN guidelines suggest that at least 15 lymph nodes (LN) should be evaluated at the time of esophagectomy to consider the lymphadenectomy 'adequate'. Despite these guidelines, this may not always be achieved in practice. The purpose of this study was to determine factors associated with adequate lymphadenectomy among patients receiving minimally invasive esophagectomy (MIE). Patients receiving MIE in the National Cancer Database from 2010 to 2016 were identified. Patients with metastatic disease were excluded. The primary endpoint was adequate lymphadenectomy, defined as >15 or greater LN evaluated. Factors associated with adequate lymphadenectomy and overall survival were evaluated in univariable and multivariable analyses. Categorical variables were assessed using chi-squared, and continuous variables were assessed with rank-sum test. Survival was evaluated using the Kaplan-Meier method. A total of 6,539 patients underwent MIE between 2010 and 2016 (5,024 thoracoscopic-laparoscopic MIE and 1,515 robotic-assisted MIE). A total of 3,527 patients (53.9%) received adequate lymphadenectomy. Receiving MIE at an academic center (odds ratio [OR] 1.37, 95% confidence interval [CI] 1.15-1.63, P < 0.001), institutional volume of MIE (OR 1.01, 95% CI 1.008-1.011, P < 0.001), and presence of clinical nodal disease (OR 1.17, 95%CI 1.02-1.33, P = 0.025) were associated with adequate lymphadenectomy. Patients with >15 LN removed had increased overall survival (46.6 vs. 41.5 months, P < 0.001). Adequate lymphadenectomy (hazard ratio [HR] 0.77, 95%CI 0.71-0.85, P < 0.001), receiving surgery at an academic center (HR 0.87, 95%CI 0.78-0.96, P = 0.007) and private insurance status (HR 0.88, 95%CI 0.81-0.98, P = 0.02) were independently associated with improved survival. Nearly half of patients receiving MIE do not receive adequate lymphadenectomy as defined by NCCN guidelines. Receiving MIE at an academic center with high procedural volume and the presence of nodal disease were independently associated with adequate lymphadenectomy. Adequate lymphadenectomy was associated with improved survival. These findings suggest that providers performing esophagectomy should follow guideline-based recommendations for lymphadenectomy.