Is the new distribution of early esophageal adenocarcinoma stages improving the prognostic prediction of the 8th edition of the TNM staging system for esophageal cancer?

ABSTRACT

BACKGROUND: The 8th edition of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system released in 2017 reclassified the pTNM stage of early esophageal adenocarcinoma from stage IA in the 7th edition to stage IA and IB and from stage IB in the 7th edition to stage IC. In this study, we analyzed the reliability of the new staging system through clinical data analysis. METHODS: We selected patient data from the Surveillance, Epidemiology, and End Results (SEER) database. From 2004 to 2014, data for a total of 714 patients were included in the study and were divided into groups representing stage IA (n=84), IB (n=386) and IC (n=244) according to the 8th edition. RESULTS: In the 8th edition, there was no significant difference between groups IA and IB in overall survival (OS) (P=0.331) or esophageal cancer-specific survival (ECSS) (P=0.341). However, the long-term survival rates of groups IA and IB were significantly higher than those of group IC. Cox regression analysis indicated that the use of new staging system does not affect prognosis. We also attempted to stratify the tumors by T stage and histological grade but found no significant difference. CONCLUSIONS: We used the SEER database to compare the staging of early esophageal adenocarcinomas between the 8th and 7th editions of the AJCC/UICC TNM staging system. Based on our data, the 8th edition is not superior to the 7th edition.