Prognostic Comparison Between Number and Distribution of Lymph Node Metastases in Patients with Right-Sided Colon Cancer

Abstract

Background. Lymph node metastasis is the most important prognostic indicator for colon cancer patients. We compared the prognostic significance of the number of lymph node metastases (LNN) and the distribution of lymph node metastases (LND). Methods. A total of 187 patients underwent curative resection for stage III right-sided colon cancer between 2000 and 2010. We evaluated the oncologic outcomes according to LNN (N1 1-3, N2 4-6, N3 >6) and LND (LND1 metastases in pericolic nodes, LND2 metastases along the major vessels, N3 metastases around the origin of a main artery). A Cox proportional hazards model, with backward stepwise analysis was used to determine the effects of covariates on 5-year, disease-free survival (DFS) and 5-year overall survival (OS). Akaike's information criterion (AIC), and Harrell's concordance index (C-index) were compared for each developed model. Results. During the median follow-up of 42.2 months, 5-year DFS and OS were 68 and 79.3 %, respectively. Multivariate analysis showed that both LNN and LND3 were independent prognostic factor for both 5-year DFS and OS. However, the prognostic model incorporating number of LNM was more precise than that of LND, with a lower AIC (5-year DFS, 554.2 vs. 566.9; 5-year OS, 318.1 vs. 337.9) and higher C-index (5-year DFS, 0.706 vs. 0.667; 5-year OS, 0.778 vs. 0.743). Conclusions. Our results show that the staging system incorporating LNN predicted prognosis better than LND.