New classification for the thoracic paraaortic lymph nodes of patients with esophageal squamous cell carcinoma

Purpose: To create a new classification for the thoracic paraaortic lymph nodes (No. 112ao) of patients with esophageal squamous cell carcinoma (ESCC). Classification of these nodes in ESCC patients has been the focus of very few reports. Methods: The subjects of this study were 27 patients with positive No. 112ao nodes on computed tomography (CT) images before treatment. We divided the No. 112ao nodes into No. 112aoA, located on the esophageal side as anterior No. 112ao nodes, and No. 112aoP, located on the opposite side of the esophagus as posterior No. 112ao nodes. We examined the association between No. 112aoA and No. 112aoP and clinicopathological factors. Recurrence-free survival (RFS) was compared between the No. 112aoA- and No. 112aoP-positive groups. Results: There were 12 patients in the No. 112aoA-positive group and 15 patients in the No. 112aoP-positive group. The No. 112aoP-positive group had significantly worse RFS than the No. 112aoA-positive group (p = 0.004). Cox multivariate analysis of RFS revealed that No. 112aoP positivity was an independent prognostic factor (p = 0.043). Conclusions: Our new classification of No. 112ao nodes into No. 112aoA and No. 112aoP is useful clinically. No. 112aoP could correspond to the clinical N4 category of patients with ESCC.