Analysis of New N Descriptors on Prognosis of Esophageal Cancer with Positive Lymph Nodes
Purpose: The 7th edition of the new TNM staining system for esophageal cancer (EC) has been published. N descriptors are now divided into N0, N1, N2 and N3. In this study, we aimed to validate the prognostic ability of the new N staging system in patients with resectable EC and positive lymph nodes, and evaluate whether the new N staging system can help the decision-making for postoperative adjuvant therapy.
Methods: From 2002 to 2008, patients with stage T1-4N1-3M0 EC who underwent esophagectomy were retrospectively analyzed. EC were classified according to the new N staging system. Kaplan-Meier method and Cox regression analysis were employed to compare overall survival (OS).
Results: A total of 545 patients met the inclusion criteria: 346 (63.5%) received esophagectomy alone, 199 (36.5%) received esophagectomy and adjuvant radiotherapy, and 36.1% (197/545) received esophagectomy and adjuvant chemotherapy. Univariate analysis and multivariate analysis revealed significant difference in OS among patients with EC at different N stages (P<0.001). Significant difference in OS was also present among patients receiving radiotherapy (P<0.001) and those undergoing chemotherapy (P<0.001). Subgroup analysis indicated that postoperative adjuvant therapy did not significantly affect the OS among patients with EC at different N stages.
Conclusions: Our results validated the prognostic ability of new N staging system. N descriptor is an independent prognostic factor in patients with resectable EC who were positive for lymph nodes. Further studies are required to clarify the role of new N staging system in the decision-making for postoperative adjuvant therapy in this population.