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 thevarious cancers, esophageal cancer is considered one of the most aggressive, with a poor survival rate. It currentlyranks eighth in incidence and sixth in mortality among all cancers, and its frequency and mortality are progressivelyincreasing, with 604,100 new cases and 5,44,000 deaths by 2020. Several staging systems have been proposedfor esophageal cancer, including the Ellis, Japan Esophageal Society, and AJCC/UICC systems. However, sincethe AJCC/UICC established their staging criteria, these have been the most widely used and accepted by themedical community.The different AJCC Cancer Staging Manual editions have progressively incorporated changes in the esophagealcancer staging as our understanding, which has been exponentially influenced by various conventional diagnosticmeans. The TNM staging system’s editions are updated periodically, but how much have they changedsince the first edition? What have been the main changes introduced in each edition concerning esophagealcancer? This narrative review aims to answer these questions through a thorough and comparative analysis ofeach TNM addition.The esophageal cancer staging has changed with each TNM edition, allowing a better understanding of itand applying better therapeutic methods. The last two editions have introduced significant changes with theincorporation of non-anatomical categories into the staging grouping and the addition of a classification for patientsundergoing neoadjuvant therapy.