Lymph node station ratio: Revised nodal category for resected esophageal squamous cell carcinoma patients.

OBJECTIVES: The objective of this study was to evaluate a revised nodal category based on the value of the lymph node (LN) station ratio (SR, metastatic LN stations/examined LN stations) in esophageal squamous cell carcinoma (ESCC) patients.

METHODS: Data were obtained from 857 ESCC patients who underwent primary radical esophagectomy. Prognostic performance was evaluated using the Harrell concordance index (C-index), Akaike information criterion (AIC), and likelihood ratio χ2 test (LR χ2 test).

RESULTS: Each subgroup among the SR categories demonstrated discriminatory results, whereas no significant survival difference was observed between the N2 versus N3 classifications under the AJCC pN system. Using the AJCC TNM staging system, the survival curves separated between stages IIIA-IIIB and IIIB-IVA. However, when the T-SR-M scheme category was applied, the survival curves between stages IIA-IIB, IIIA-IIIB, and IIIB-IVA were significantly different. Furthermore, both the SR category and the T-SR-M staging system showed superior performance with higher C-index and LR χ2 test values and lower AIC values compared with the pN category and TNM staging system, respectively.

CONCLUSIONS: Following radical esophagectomy, the SR category demonstrated superior prognostic ability relative to the AJCC pN category in ESCC patients.