RESUMEN
The 8th edition of TNM cancer staging is based on data from large patient cohorts, data collected from the Worldwide Collaboration Cancer Esophageal (WECC) group, or the International Association for Gastric Cancer (IGCA), including treated patients surgically per primate or after neoadjuvant treatment. This edition redefines the esophago-gastric junction tumors and recommends different TNMs staging: Siewert type I and II should be classified according to TNM recommendations for esophageal adenocarcinoma, while for Siewert type III the TNM classification for gastric cancer should be considered. Anatomical characteristics feature type T (tumor invasion), type N (regional lymph node invasion) and type M (distant metastasis). Non-anatomic characteristics include tumor differentiation (G) and tumor localization (L). Category descriptors are currently evaluated by endoscopy with biopsy, fine needle aspiration (EUS-FNA), thoraco-abdomino-pelvic computer tomography (CT) and positron emission tomography (CT-PET). The new TNM staging edition presents separate classifications applicable for therapeutic strategy: clinical staging cTNM (prior to any treatment), pathological staging pTNM (after surgery first) and neoadjuvant pathologic staging ypTNM (after neoadjuvant treatment followed by surgery). The refinement of each category and subcategory of T, N, M makes the 8th edition more accurate and adaptable to current practice, including for therapeutic strategy. The purpose of this study is to evaluate the clinical and therapeutical implications of the 8th edition of the TNM staging for esophago gastric junction adenocarcinoma.