The N ratio predicts recurrence and poor prognosis in patients with node-positive early gastric cancer.

Abstract

The metastatic status of the regional node is the most significant prognostic factor for early gastric cancer (EGC). However, diverse prognoses are evident even among the same N classifications of the current tumor-node-metastasis system. The aim of this study was to evaluate the prognostic significance of the ratio of metastatic to retrieved lymph nodes (N ratio) in identifying a high-risk subgroup with node-positive EGC. From a prospective database of 1264 EGC patients between 1987 and 1997, 156 (12.4%) were found to have histologically confirmed node metastasis. A number of prognostic factors, including the N ratio, were evaluated by univariate and multivariate analysis. The recurrence rate of node-positive EGC was 16.7% (n = 26). The overall 5-year survival rate of all patients was 84.0%. It was 26.9% and 95.4% in patients with and without recurrence, respectively (P < .0001; log-rank test). The cutoff value of the N ratio was set at .07. The 5-year survival rate of patients with an N ratio <.07 was 94.0%; this was significantly higher than the rate (72.6%) for those with a ratio >.07 (P < .0001; log-rank test). Both univariate and multivariate analysis identified the N ratio as the most significant predictive factor for recurrence and overall survival. Regarding stage migration, it shows superiority in comparison to the number-based N classification. The N ratio is a more effective and rational indicator for prognostic stratification of patients with lymph node-positive EGC than the current N classification of the tumor-node-metastasis system.