[Comparison of Current Perspectives of Perioperative Treatments for Esophageal Cancer between Japan and the Western Countries-Toward International Collaborative Studies].

There are 2 main histologic types of esophageal cancer: squamous cell carcinoma and adenocarcinoma. Squamous cell carcinoma is the most common histology type in the world, but in Europe and the United States, adenocarcinoma is the most common type. The standard treatments differ between Japan and the Europe and the United States, especially in the perioperative treatments. Standard treatment in Japan is preoperative chemotherapy based on the results of the JCOG1109 trial. While in Europe and the United States, the standard treatment is preoperative chemoradiotherapy based on the results of the CROSS trial and postoperative nivolumab according to the results of CheckMate 577 trial. In surgical treatment, 3- region lymph node dissection is the standard in Japan, whereas in Europe and the United States, where the lower esophagus, mainly adenocarcinoma, is often treated, 2-region lymph node dissection of the middle and lower mediastinum is the standard. Due to these differences in established treatments, the results of clinical trials in other countries cannot be extrapolated to standard treatment in Japan. Therefore, it is essential to understand the differences in standard treatment in East Asia, where esophageal squamous cell carcinoma frequently occurs, and other countries, and to deepen exchanges with experts in each country, so that international clinical trials can be designed and standard treatment can be established.