A new clinical staging system for esophageal cancer to predict survival after definitive chemoradiation or radiotherapy.

This study is to evaluate the prognostic value of a new clinical staging system for esophageal cancer to predict survival after (chemo)radiotherapy. This retrospective study enrolled 444 patients with esophageal squamous cell carcinoma who underwent definitive intensity-modulated radiotherapy with or without chemotherapy between January 2008 and May 2014. A clinical staging system based on the gross tumor volume and maximum diameter of metastatic lymph nodes was developed and the prognostic value of this staging system was compared with that of the 8th edition of American Joint Committee on Cancer TNM staging system. The 3-year survival rate in the whole group was 44.5%. Multivariate analysis showed that gross tumor volume and maximum diameter of metastatic lymph nodes were independent prognostic factors. According to the proposed clinical staging system, the 3-year survival curves of each T, N, and TNM stage were well segregated. On the other hand, 3-year survival rates based on the 8th edition of cTNM staging system were similar between cT3 and cT4, cN1 and cN2, cN2, and cN3, III and IVa stages.The proposed clinical staging system appears to be a simple and accurate predictor of outcome in patients with esophageal squamous cell carcinoma who underwent definitive (chemo) intensity-modulated radiotherapy.