Stage Classifications: The UICC/AJCC Classifications and the Japanese Classification

Abstract

The history, TNM categories, stage grouping, and related categorizations are compared between the TNM/AJCC stage classifications and the JES stage classification—Japanese Classification of Esophageal Cancer. The most commonly used staging system throughout the world is the TNM Classification of Malignant Tumours which is published collaboratively by the UICC and the AJCC. On the other hand, the Japanese Classification of Esophageal Cancer is used throughout Japan and rarely in other countries. There is a large difference between the UICC/AJCC Classifications and the JES Classification in the definition of the esophagogastric junction for adenocarcinoma and in the N categories. The esophagogastric junction is defined based on Siewert’s Classification in the UICC/AJCC Classifications, while it is defined based on the Nishi’s Classification in the Japanese Classification. The N categories are classified by the number of metastasis-positive lymph nodes in the UICC/AJCC Classification, whereas they are classified by the spread of metastasis-positive lymph nodes in the JES Classification. The UICC/AJCC consider that stage classification should be based on prognostic outcomes only, while the JES consider that stage classification should be based on clinical prognostic outcomes and additionally should play a role in the guidelines for lymphadenectomy.