Patterns and Influence of Lymph Nodal Metastases After Neoadjuvant Chemotherapy and Surgery for Thoracic Esophageal Squamous Cell Carcinoma

PurposeThe purpose of this retrospective study was to define the pattern of lymph nodal metastases in patients with esophageal squamous cell carcinoma (ESCC) after neoadjuvant chemotherapy (NCT) followed by esophagectomy and to evaluate its influence on prognosis.MethodsA total of 398 patients with clinical stage T3N0 or T1-3N+ ESCC who underwent NCT and radical esophagectomy with two-field lymphadenectomy were included. The distribution and frequency of metastases were counted separately for each lymph node station. The ypN stage, number of positive lymph node stations and lymph node stations with a metastasis rate greater than 5% were analyzed by using univariate Cox regression, followed by separate multivariable Cox regression analyses after adjusting for various clinical factors.ResultsLymph node metastases were most frequently observed in the right upper paratracheal (16.8%) and left gastric artery (13.1%) stations. Multivariable models controlling for clinical factors showed that ypN stage remained a significant independent predictor of survival (N1 vs. N0: hazard ratio [HR], 2.30, 95% confidence interval [CI] 1.38-3.83, P < 0.001; N2 vs. N0: HR, 3.76, 95% CI 2.21-6.38, P < 0.001; N3 vs. N0: HR, 7.14, 95% CI 3.78-13.48, P < 0.001). The model from the multivariable analysis with the highest c-index score, indicating superior discriminatory preference, was ypN stage (c-index, 0.72).ConclusionsThe pattern and influence of lymph node metastases after NCT will provide guidance on the extent of lymphadenectomy. Common positive lymph node stations for thoracic ESCC after NCT include the paratracheal, subcarinal, paraesophageal, paracardial, and left gastric artery stations.