The Validity of Predicting Prognosis by the Lymph Node Ratio in Node-Positive Colon Cancer

Abstract

Background/Aims: Because the TNM system disregards the number of lymph nodes dissected and inter-individual differences exist in the number of regional lymph nodes, the lymph node ratio (LNR), which is estimated by dividing the number of metastatic lymph nodes by the number of dissected lymph nodes, has been proposed as a prognostic factor in recent years. The purpose of the present study is to examine the validity of predicting prognosis using the LNR in node-positive colon cancer. Methods: Three hundred and eleven patients with lymph node metastases who underwent curative surgery for colon cancer at our department between 1992 and 2005 were enrolled. Univariate and multivariate analyses were performed to evaluate the relationship between clinicopathological factors and prognosis. Results: Among the patients with ≥12 dissected lymph nodes, differentiation, invasion depth and TNM N category were found to be significant independent prognostic factors. On the other hand, among the patients with ≤11 dissected lymph nodes, differentiation and the LNR were found to be significant independent prognostic factors. Conclusion: Among the patients with ≤11 dissected lymph nodes, LNR was a significant independent prognostic factor.