Novel pathological staging for patients with locally advanced esophageal squamous cell carcinoma undergoing neoadjuvant chemotherapy followed by surgery

Background The aim of the present study was to clarify an appropriate staging system for patients with locally advanced esophageal squamous cell carcinoma (LAESCC) after neoadjuvant chemotherapy (NAC) prior to surgery. Methods A total of 388 patients with clinical stage II or III LAESCC who had undergone NAC followed by an esophagectomy with three-field lymphadenectomy were retrospectively reviewed. Results The relapse-free survival (RFS) curves plotted using ypN grading and ypTNM staging both monotonically decreased as the classification number increased, and the groups were more clearly separated than when the Japanese Classification (JC) was applied. A multivariate analysis of relapse free survival (RFS) suggested that ypN (HR = 2.911, P < 0.001), lymphovascular invasion (LVI) (HR = 2.608, P < 0.001) were independent factors associated with OS. The LVI+/ypN+ group had a significantly poorer outcome than the other groups (P < 0.001). The 5-year RFS rates for patients with ypStage IIIA or higher among the LVI-negative cases and ypStage II or higher among the LVI-positive cases were around 0.6 or under. The novel pathological staging which was based on the present results was proposed and RFS curves of each novel stage suggested the suitability of these staging for our cohort. Conclusions The present results suggest that a novel pathological staging system using the ypTNM classification, in which the supraclavicular lymph node was regarded as a regional lymph node and the presence of LVI was included as a category, was appropriate for patients with LAESCC after NAC prior to surgery.