Comparison of tumor regression grading system in locally advanced esophageal squamous cell carcinoma after preoperative radio-chemotherapy to determine the most accurate system predicting prognosis

Esophageal cancer (EC) is the seventh most common cancer and is the sixth leading cause of cancer death worldwide (1). Esophageal squamous cell carcinoma (ESCC) is the most common type of EC, followed by esophageal adenocarcinoma (EAC). ESCC is more common in Asia and Africa (2). The incidence and type of cancer vary by region of the world. In the western world, the incidence of ESCC has been reduced and that of EAC is higher (3). In Asian countries, the incidence of ESCC is still more than 90%, and is a major health burden (2,4). Smoking and alcohol consumption are the main risk factors for ESCC. Inadequate consumption of vegetable and fruit, and low socioeconomic status are also risk factors (4)