Proposed modification of nodal status in AJCC esophageal cancer staging system

Abstract

Background: The current American Joint Committee on Cancer (AJCC) esophageal cancer staging for nodal status is difficult to interpret and is based solely on lymph node location relative to the primary tumor's esophageal location. Recent reports suggest that the number of lymph nodes involved is also an important factor. We reviewed our esophageal experience to propose an improved nodal staging system.

Methods: In all, 1,027 patients with resected esophageal cancer from 1970 to 2005 were reviewed. Lymph nodes stations were assigned according to AJCC criteria. Overall survival was assessed by Kaplan-Meier analysis. The impact of location, number of involved lymph nodes, and use of preoperative chemotherapy or radiation therapy, or both, was assessed.

Results: Nonregional nodal involvement (n = 17) was associated with decreased survival compared with regional (n = 441) or celiac nodal (n = 73) involvement (3-year: 0% versus 24% and 23%; p < 0.001). The number of involved lymph nodes was strongly associated with survival (3-year: 0 nodes = 63%, 1 to 3 nodes = 31%, more than 3 nodes = 13%; p < 0.001), and multivariable Cox proportional-hazards analysis suggested that the location and number of involved lymph nodes were independent predictors of survival (p < 0.001). We propose a modified nodal staging system that designates celiac nodes as regional and includes number of involved nodes: pN0, no nodes (3 years = 63%, n = 496); pN1-regional, 1 to 3 nodes (3 years = 32%, n = 292); pN2-regional, more than 3 nodes (3 years = 14%, n = 222); pN3-nonregional node (3 years = 0%, n = 17 [p < 0.0001]). This modified nodal staging system better predicts survival than the current AJCC nodal staging system in which survival for pN1 (3 years = 24%) and pM1a (3 years = 23%) do not differ (p = 0.67). The use of induction before surgical resection did not alter the predictive effect of the new nodal staging system.

Conclusions: Modification of the AJCC nodal classification system to incorporate the number of involved lymph nodes with regional and nonregional node location simplifies and better predicts long-term survival than does the current AJCC nodal system.