The new Japanese Classification of Gastric Carcinoma: Points to be revised

Abstract

SUMMARY OF CHANGES:1. The previous version described clinical, surgical and conclusive staging. This version retains clinical and surgical staging, being the staging before and during definitive surgery respectively. Conclusive staging is now defined as final staging, and may include information for which there is no histological proof (e.g. hepatic metastases). Pathological staging has been introduced, and requires microscopic proof.2. Lymph node staging has been extensively revised. A 3 tier system replaces the previous 4 tier system, and thus there are now 4 possible N stages (N0-3). The definition of some node groupings have been more precisely defined (No.11 and No.12).3. Lymph node dissection is classified D0-3 based on the new nodal groups. Minor modifications of the extent of dissection have been made. "Optional" stations have been omitted.4. Peritoneal cytology has been included in the staging system.6. Rules for staging carcinoma of the remnant stomach have been introduced.7. Rules to classify and evaluate endoscopic mucosal resection (EMR) have been introduced.8. Subclassification of T staging has been introduced for T1 (M and SM) and T2 (MP and SS) tumors.9. Nomenclature has been simplified: lower case letters are only used to define the "type" of staging (c clinical; s surgical; p pathological; f final). Tumor location is now defined as U (upper third), M (middle) or L (lower), replacing C, M, A. Proximal and distal margins are designated as PM and DM (previously OW and AW). LM and VM have been introduced for the lateral and vertical margins of EMR specimens.