The goal of this multicenter retrospective cohort study is to evaluate the impact of different pathological regression types on survival and recurrence patterns, with a particular focus on ypT0N+ patients in patients with esophageal squamous cell carcinoma. The main questions it aims to answer are the survival and recurrence patterns among the different pathological regression types in patients with esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy.