TNM system for staging esophageal cancer: A narrative review

Abstract

Cancer is a critical health concern worldwide, and this chronic disease is gradually growing. In 2020 alone, 19,292,789 new cases were reported globally; by 2025, this figure is expected to rise to 21,618,445. Among the various cancers, esophageal cancer is considered one of the most aggressive, with a poor survival rate. It currently ranks eighth in incidence and sixth in mortality among all cancers, and its frequency and mortality are progressively increasing, with 604,100 new cases and 5,44,000 deaths by 2020. Several staging systems have been proposed for esophageal cancer, including the Ellis, Japan Esophageal Society, and AJCC/UICC systems. However, since the AJCC/UICC established their staging criteria, these have been the most widely used and accepted by the medical community. The different AJCC Cancer Staging Manual editions have progressively incorporated changes in the esophageal cancer staging as our understanding, which has been exponentially influenced by various conventional diagnostic means. The TNM staging system’s editions are updated periodically, but how much have they changed since the first edition? What have been the main changes introduced in each edition concerning esophageal cancer? This narrative review aims to answer these questions through a thorough and comparative analysis of each TNM addition. The esophageal cancer staging has changed with each TNM edition, allowing a better understanding of it and applying better therapeutic methods. The last two editions have introduced significant changes with the incorporation of non-anatomical categories into the staging grouping and the addition of a classification for patients undergoing neoadjuvant therapy