Development of an optimal staging system for esophageal cancer is essential to estimate prognostic factors accurately and treat them appropriately. In this study, we evaluated the surgical outcomes of esophageal cancer according to five existing staging systems and assessed their prognostic significance.

For 113 patients with esophageal cancer who had undergone curative resection, lymph-node metastasis was classified using the 8th and 9th editions of the Japanese classification, the 6th edition of the Union Internationale Contre le Cancer (UICC) TNM classification, and systems based on the number (0, 1 to 3, or ≥4) or ratio (0, <0.15, or ≥0.15) of metastatic lymph nodes. Survival and prognostic factors of the respective stages were evaluated.

Univariate analysis of disease-specific survival revealed that depth of invasion and lymph-node classification notably affected prognosis. Multivariate analysis confirmed that each classification independently influenced prognosis. According to the criteria of the two Japanese classifications, there was no clear correlation between lymph-node stage and survival. The Union Internationale Contre le Cancer /TNM classification, and those based on the number or ratio of metastatic lymph nodes showed a clear correlation between lymph-node metastasis and survival. These systems had better stratification than the Japanese classifications.

Staging systems for esophageal cancer based on the number or ratio of metastatic lymph nodes showed better prognostic significance than those based on the anatomic distribution of metastatic lymph nodes, because of their good stratification and clinical utility. Such classifications are suitable for use throughout the world.