The metastatic lymph node ratio predicts survival in colon cancer

BACKGROUND: Lymph node metastases are the most important predictor of survival in non-stage IV colon cancer. Recent studies of gastric cancer have shown a prognostic significance of a lymph node ratio (number of positive nodes divided by total number harvested). Our goal was to determine whether a lymph node ratio (LNR) would predict disease-free survival (DFS) and overall survival (OS) in a tertiary care Veterans Affairs medical center. METHODS: A retrospective review of a prospectively collected database of colon cancer patients was performed to determine the effect of LNR on DFS and OS. A cohort of 232 patients with non-stage IV colon cancer was eligible for analysis. Survival curves were constructed using the Kaplan-Meier method. RESULTS: For all patients, a LNR of .08 was identified as a breakpoint for predicting OS and DFS. Specific analysis of stage III patients revealed that a LNR of .18 was predictive of DFS. CONCLUSIONS: This study showed the prognostic significance of ratio-based staging for colon cancer and may aid in future staging systems.