A revised postneoadjuvant pathologic stage grouping for esophageal squamous cell carcinoma: A dual-center study

The 8th American Joint Committee on Cancer postneoadjuvant pathologic stage grouping is the current standard for risk stratification after neoadjuvant therapy and esophagectomy. However, its prognostic ordering may be unstable in esophageal squamous cell carcinoma, particularly across intermediate stage groups.

Patients with esophageal squamous cell carcinoma who underwent neoadjuvant therapy followed by esophagectomy at two centers were retrospectively identified. The West China Hospital cohort was used for development, and the First Affiliated Hospital of Zhengzhou University cohort was used for external validation. Recursive partitioning analysis using routine ypT and ypN categories was applied to develop a revised stage grouping. Prognostic ordering, model fit, and discrimination were compared with the 8th American Joint Committee on Cancer postneoadjuvant stage grouping.

Among 1486 patients, 872 were included in the development cohort and 614 in the validation cohort. The revised system grouped patients into 5 prognostic categories and restored an ordered survival gradient in both cohorts, whereas the current American Joint Committee on Cancer stage showed survival overlap and inversion between stages II and IIIA. The revised system showed higher linear trend chi-square and likelihood ratio chi-square values and lower Akaike information criterion values in both cohorts. Concordance index and time-dependent area under the curve values were comparable between the two systems.

The revised ypT/ypN-based stage grouping improved prognostic ordering and model fit in esophageal squamous cell carcinoma, while maintaining comparable discrimination. This approach may support postoperative risk stratification after neoadjuvant therapy and esophagectomy.