O2-036 - Recursive Partitioning for New Classification of Patients with Esophageal Cancer Treated by Chemoradiotherapy

Abstract

ABSTRACT Background The 7th edition of the American Joint Committee on Cancer staging system does not include lymph node size in the guidelines for staging patients with esophageal cancer. The objectives of this study were to determine the prognostic impact of the largest lymph node diameter (ND) on survival and to develop and validate a new staging system for patients with esophageal squamous cell cancer who were treated with definitive chemoradiotherapy (CRT). Methods Information on 402 patients with esophageal cancer undergoing CRT at two institutions was reviewed. Univariate and multivariate analyses of data from one institution were used to assess the impact of clinical factors on survival, and recursive partitioning analysis was carried out to develop the new staging classification. To assess its clinical utility, the new classification was validated using data from the second institution. Results According to RPA, ND stages were best when classified as ND0 (the absence of lymph node metastases), ND1 ( 2.8 cm). By multivariate analysis, gender, T, N, and ND stages were independently and significantly associated with survival (P Conclusions Our results showed that the lymph node size is a strong independent prognostic factor and that the new staging system, which incorporated lymph node size, provided good prognostic power and discriminated effectively for patients with esophageal cancer undergoing CRT.