Hsu PK, et al. - Although clinical (c), pathological (p), and post-neoadjuvant pathological (yp) stage groups can be distinguished using the 8th edition American Joint Committee on Cancer Tumour-Nodes-Metastasis (TNM) staging system, the ability to discriminate between ypStage II and ypStage III is poor. Researchers, therefore, conducted this study to determine prognostic factors in patients with ypStage II/III esophageal squamous cell carcinoma. They retrospectively reviewed the data of 150 patients with ypStage II/III esophageal squamous cell carcinoma from 2 medical centers, and, upon analysis, found that incorporation of the existence of perineural invasion after neoadjuvant treatment into the TNM staging system may improve discrimination between patients with ypStage II/III esophageal squamous cell carcinoma as it is closely associated with poor prognosis.