Prognostic impact of lymph node harvest for patients with node-negative esophageal squamous cell carcinoma: a large-scale multicenter study

Nodal Yield <15 Is Associated With Reduced Survival in Esophagectomy and Is a Quality Metric

BACKGROUND

Surgical resection after neoadjuvant therapy remains the cornerstone of curative management of esophageal adenocarcinoma and is frequently used for squamous cell carcinoma. The optimal extent of lymphadenectomy and whether increasing lymph node yields confer a survival benefit remains unclear. Guidelines suggest resecting and examining a minimum of 15 lymph nodes at esophagectomy. This study assessed the impact of lymph node yield and lymph node ratio (LNR) on survival, identifying factors influencing nodal yield and radicality of resection.

METHODS

All patients undergoing esophagectomy with curative intent at a single institution (stage 1-4 inclusive) from January 1, 2010, to December 31, 2020, were reviewed. Clinical and pathologic variables were interrogated. LNR was calculated by dividing positive lymph nodes by the total nodes resected.

RESULTS

Esophagectomy was performed in 397 patients, with 288 undergoing minimally invasive esophagectomy (MIE). Margin status (hazard ratio [HR], 1.80; 95% CI, 1.15-2.83; P < .01), nodal yield <15 (HR, 1.98; 95% CI, 1.29-3.04; P = .002), and elevated LNR (HR, 8.16; 95% CI, 2.89-23.06; P < .001) predicted survival. MIE had higher nodal yields compared with open procedures (30.7 vs 25.3, P < .001). Patients undergoing neoadjuvant chemoradiotherapy had lower nodal yields compared with those with no neoadjuvant therapy and those with neoadjuvant chemotherapy (26.4 vs 30.6 vs 36.8, respectively; P < .001). Regression analysis determined a LNR of <0.05 was associated with a survival benefit.

CONCLUSIONS

Textbook lymphadenectomy is associated with improved survival. Low lymph node yield and a high LNR are associated with reduced overall survival. A LNR of <0.05 is associated with significant survival benefit. A minimum nodal yield of 15 should remain the standard of care.

Development and validation of nodal staging score in pN0 patients with esophageal squamous cell carcinoma: A population study from the SEER database and a single-institution cohort

BACKGROUND

Patients with esophageal squamous cell carcinoma (ESCC) with lymph node metastasis may be misclassified as pN0 due to an insufficient number of lymph nodes examined (LNE). The purpose of this study was to confirm that patients with ESCC are indeed pN0 and to propose an adequate number for the correct nodal stage using the nodal staging score (NSS) developed by the beta-binomial model.

METHODS

A total of 1249 patients from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2017, and 1404 patients diagnosed with ESCC in our database between 2005 and 2018 were included. The NSS was developed to assess the probability of pN0 status based on both databases. The effectiveness of NSS was verified using survival analysis, including Kaplan-Meier curves and Cox models.

RESULTS

Many patients were misclassified as pN0 based on our algorithm due to insufficient LNE. As the number of LNE increased, false-negative findings dropped; accordingly, the NSS increased. In addition, NSS was an independent prognostic indicator for pN0 in patients with ESCC in the SEER database (hazard ratio [HR] 0.182, 95% confidence interval [CI] 0.046-0.730, p = 0.016) and our database (HR 0.215, 95% CI 0.055-0.842, p = 0.027). A certain number of nodes must be examined to achieve 90% of the NSS.

CONCLUSIONS

NSS could determine the probability of true pN0 status for patients, and it was sufficient in predicting survival and obtaining adequate numbers for lymphadenectomy.