The Ideal Number of Examined Lymph Node Stations for Accurate Nodal Staging and Prognosis in Pathological T1-2 Esophageal Squamous Cell Carcinoma: A Large-Scale Multicenter Cohort Study.

Esophagectomy is the standard treatment for pathological T1-2 (pT1-2) esophageal squamous cell carcinoma (ESCC). However, the optimal extent of lymphadenectomy remains controversial. The number of examined lymph node stations (ELNS) may define dissection extent. This study aims to determine optimal ELNS for accurate nodal staging and overall survival (OS) benefit in patients with pT1-2 ESCC. Multicenter data of patients with pT1-2 ESCC undergoing esophagectomy with lymphadenectomy were included. The association of ELNS count with accurate nodal staging and OS was evaluated using multivariate models. Chow test was performed to identify structural breakpoints of ELNS count. Subgroup analyses and integrated time-dependent area under the curve (iAUC) were used to validate the effectiveness of the models. Among 1423 patients, the model identified five and seven as breakpoints for accurate nodal staging and OS, respectively (all P < 0.05). In multivariate analysis, ≥ 5 ELNS (P = 0.008) was an independent predictive factor of lymph node involvement detection, while = 7 ELNS (P = 0.015) was an independent prognostic factor for OS. Patients with 7 ELNS removed demonstrated superior OS compared with others (P = 0.026). The predictive accuracy for lymph node involvement detection was improved in ≥ 5 ELNS group (AUC, 0.68 versus 0.64). Furthermore, a higher prognostic value was found in patients with 7 ELNS (iAUC, 0.76 versus 0.65). ELNS = 5 is established as the optimal threshold for ensuring nodal staging adequacy and ELNS = 7 as the optimal threshold for maximizing OS benefits in patients with pT1-2 ESCC.