CEACAM5 and esophageal squamous cell carcinoma: Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two main pathological types of EC.The detection rate and accuracy of imaging examinations for EC are limited due to the occult early symptoms and relatively limited lesion scope.At the same time, the EC clinical tumor markers (cytokeratin 19 fragment, squamous cell carcinoma antigen and carcinoembryonic antigen) in the detection and lack of ideal sensitivity and specific degrees (3, 4).