Metastatic lymph node ratio is a more precise predictor of prognosis than number of lymph node metastases in stage III colon cancer

Abstract

The objective of this study is to assess the value of metastatic lymph node ratio (LNR) in predicting disease-free survival (DFS) in patients with stage III adenocarcinoma of the colon. From 1995 to 2003 inclusively, a total of 624 patients featuring stage III adenocarcinoma of the colon underwent curative resection. Of the 624 patients, an adequate number of lymph nodes (n > or = 12) had been harvested in 490 patients. These patients were stratified into LNR groups 1 (LNR < or = 0.4), 2 (0.4 < LNR < or = 0.7), and 3 (LNR > 0.7). Kaplan-Meier survival curve and log-rank test were used to evaluate the prognostic value of LNR. A Cox regression model was used for multivariate analyses. The 5-year DFS rate was 66.7% for patients with LNR1, 35.1% for those with LNR2, and 0% for patients with LNR3 (p < 0.0001). In T3/4LNR1 patients (n = 411), there was no difference in survival between those with N1 stage and those with N2 stage. Cox proportional hazards regression analysis revealed that N stage (number of positive lymph nodes) was not a significant factor when LNR was taken into consideration. LNR is a more precise predictor of 5-year DFS than number of positive lymph nodes (N stage) in patients with stage III colon cancer.