Prognosis of patients with esophageal squamous cell carcinoma who achieve major histopathological response after neoadjuvant chemoradiotherapy.

BACKGROUND: The purpose of this study was to investigate the prognosis and its predictors in patients with esophageal squamous cell carcinoma (ESCC) who achieve major histopathological response (MaHR) after neoadjuvant chemoradiotherapy (nCRT). METHODS: We examined a total of 187 ESCC patients who achieved MaHR following nCRT and survived the perioperative period. MaHR was defined as either absence or <10% vital residual tumor cells (VRTC) in the resected esophagus without nodal involvement. Univariate and multivariate analyses were used to identify factors significantly associated with overall survival (OS). RESULTS: At the time of analysis, 113 patients (60.4%) were dead (5-year OS = 48%; median survival time = 54.8 months). The amount of VRTC (1-10% versus 0% VRTC; hazard ratio [HR] = 1.9, P < 0.001) and the thoroughness of histopathological examination (standard [≤ 4 tumor blocks] versus thorough [> 4 tumor blocks], HR = 1.57; P = 0.013) were independent predictors of OS in multivariate analysis. A stepwise increase in OS was observed in the following groups: patients with 1-10% VRTC identified by the standard protocol, patients with 1-10% VRTC identified by the thorough protocol, patients with 0% VRTC identified by the standard protocol, and patients with 0% VRTC identified by the thorough protocol (5-year OS rates = 20%, 40%, 50%, and 62%, respectively, P < 0.001). CONCLUSIONS: In ESCC patients who achieve MaHR after nCRT, the presence of microscopical residual disease and the thoroughness of histopathological examination are associated with survival.