Fig. 1

Patient screening flowchart. This figure not only shows how we screened total ESCA cases (n = 16,805), cases with upper ESCA (n = 1371) and cases with ESCA at other segments (n = 15,434), but also shows the upper ESCA model and TNM model developed from upper ESCA cases and the total ESCA model developed from total ESCA cases. ESCA esophageal cancer.