Prognostic impact of sterilized lymph nodes in esophageal squamous cell carcinomas after neoadjuvant chemoradiotherapy.

Background: The prognostic importance of sterilized lymph nodes (SLN) remains unclear in patients with esophageal squamous cell carcinomas (ESCC) treated by neoadjuvant chemoradiotherapy (nCRT). This study aimed to determine whether SLN predicted disease-free survival (DFS) in ESCC.

Methods: We enrolled 246 eligible patients who were divided into SLN (+) and SLN (-) group according to the presence or absence of fibrosis, necrosis, calcifications and/or foreign body giant cell reactions in the negative lymph nodes specimens. The prognostic value of SLN was determined using univariate and multivariate analyses. The prognostic strength of counting SLN as positive lymph nodes was evaluated using the difference of Akaike information criterion (ΔAIC).

Results: A total of 61 SLN were identified in 38 (15.4%) patients. There was no significant difference in baseline characteristics between SLN (+) and SLN (-) group. The most frequently detected SLN in the thoracic cavity and abdominal cavity were those along bilateral recurrent laryngeal nerve (21/38,55.3%) and left gastric artery (13/24,60.9%), respectively. The univariate and multivariate analyses showed SLN was an independent prognostic factor for worse DFS in the whole cohort (HR = 2.05, 95%CI = 1.08-3.90, P = 0.029). The SLN (+) group additionally correlated with worse 5-year DFS than SLN (-) group in the ypT0, ypN0 and pCR subgroups. Counting SLN as positive lymph nodes showed better prognostic strength than ignoring them.

Conclusion: SLN was of prognostic significance for worse DFS in patients with ESCC, particularly in patients with good response to nCRT.