[Key updates in the 16th edition of the japanese classification of gastric carcinoma]

This article summarizes the major updates in the 16th edition of the Japanese Classification of Gastric Carcinoma. Based on its established framework, the revision enhances alignment with the 9th edition of the TNM staging system, the Japanese Classification of Esophageal Cancer, and the WHO Classification (6th edition). The updated edition standardizes the definition and description of esophagogastric junction carcinoma and shortens specimen fixation time to better support molecular testing. In staging, Tis has been introduced and T category definitions have been refined, with removal of outdated subclassifications to improve clarity in assessing tumor invasion depth. Classification of lymph node station and the grading of hepatic and peritoneal metastases have been further detailed. The inclusion of the Peritoneal Cancer Index and standardized peritoneal lavage cytology criteria enhances the evaluation of distant metastasis. In pathology, histological classifications have been updated, and several subtypes are more clearly defined. The Becker tumor regression grading system has also been incorporated to assess treatment response in line with international standards. Overall, these updates improve the standardization, comparability, and global applicability of gastric cancer diagnosis and treatment, supporting better clinical decision-making and facilitating multicenter research.