Kurokawa Y, Takeuchi H, Doki Y, et al. - Researchers conducted a prospective nationwide multicenter study investigating the optimal extent of lymph node dissection for the 2 histological types of esophagogastric junction (EGJ) tumors based on the incidence of metastasis. They enrolled patients with cT2-T4 adenocarcinoma or squamous cell carcinoma located within 2.0 cm of the EGJ before surgery. In these patients, either the abdominal transhiatal or right transthoracic approach was used to perform dissection of all lymph nodes prespecified in the protocol. Classification of lymph nodes was done according to metastasis rate: category-1 (strongly recommended for dissection), rate more than 10%; category-2 (weakly recommended for dissection), rate from 5% to 10%; and category-3 (not recommended for dissection), rate less than 5%. Of 1,065 screened patients with EGJ tumor, 371 were enrolled. Surgical resection was performed on 358 patients, category-1 nodes included abdominal stations 1, 2, 3, 7, 9, and 11p, whereas category-2 nodes included abdominal stations 8a, 19, and lower mediastinal station 110. Station 110 was assigned to category-1 when esophageal involvement exceeded 2.0 cm. Among 98 patients who had either adenocarcinoma with esophageal involvement over 3.0 cm or squamous cell carcinoma, no category-1 nodes in the upper/middle mediastinal field was reported, whereas category-2 nodes comprised upper mediastinal station 106recR and middle mediastinal station 108. Station 106recR was assigned to category-1 when esophageal involvement exceeded 4.0 cm.