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.