An attempt at validation of the Seventh edition of the classification by the International Union Against Cancer for esophageal carcinoma

Abstract

Background: The aim of our study was to investigate the ability of the Seventh edition of the classification by the International Union Against Cancer (UICC) to identify patients at higher risk and to predict the overall survival in patients with esophageal carcinoma.

Methods: Demographic and clinical data of 605 patients, who underwent esophagectomy for esophageal carcinoma between 1992 and 2009, were analyzed. Tumor stage and grade were classified according to the sixth and seventh editions of the UICC classification.

Results: Tumor depth (T), lymph node affection (N), and metastasis (M) status according to the seventh edition of the UICC classification showed significant differences in survival of each single status. Kaplan-Meier analysis of overall survival by the seventh edition of the UICC classification showed poor discrimination between stages Ib and IIa (p=0.098), stages IIIa and IIIb (p=0.672), and stages IIIc and IV (p=0.799). Further, the estimated median survival time between stages IIa and IIb was discordant.

Conclusions: The seventh edition of the UICC TNM classification cannot satisfactorily distinguish among different risk groups of patients with resected esophageal carcinoma. The new subgroups do not unify the different TNM stages with similar survival. We strongly propose that the next revision of the UICC classification should reduce the stages to groups with similar survival, without defining complex subgroups.