Abstract
BACKGROUND: The status of lymph node (LN) metastases in esophageal squamous cell carcinoma (ESCC) following neoadjuvant chemoradiation (NCRT) is not well understood but significantly affects patient prognosis and treatment options. We conducted this study to evaluate the distribution of LN metastases in patients with ESCC who received NCRT combined minimally invasive esophagectomy (MIE). METHODS: From March 2019 to September 2023, patients with middle- and lower-third ESCC received NCRT, followed by MIE with two-field lymphadenectomy, were included in this study. The primary outcome was to examine the distribution of LN metastases and their correlation with the radiation fields. Secondary outcomes included identifying risk factors for LN metastases and their impact on long-term survival. RESULTS: One hundred consecutive patients were included, and 4.11% had LN metastases. The median number of positive LN and the rate of LN metastases in the thoracic LN stations was lower than that of the abdominal region (1.5 and 2.84% vs. 2 and 5.94%, respectively). Over half of the patients had LN metastases within the radiation field. The multivariate analysis found that the LN metastases were associated with the ycN-stage [hazard ratio (HR) =2.03, 95% confidence interval (CI): 1.02-4.04, P=0.04]. Although the LN metastases were not significantly associated with either overall survival (OS) or disease-free survival (DFS) (P=0.89 and P=0.65, respectively), the number of LN removal ≥15 LN removals was significantly improved both OS and DFS (P=0.040 and P=0.049, respectively). CONCLUSIONS: In patients with middle- and lower-third ESCC who underwent NCRT followed by MIE, the rate of LN metastases in the abdominal region is higher than in the thoracic region. The majority of patients had LN metastases within the radiation field. Therefore, NCRT does not justify minimizing lymphadenectomy in ESCC; furthermore, a higher ycN-stage correlated with a higher incidence of LN metastases; higher ycN-stage correlates with higher LN metastases.