Clinical Significance of Lymph Node Ratio in Stage III Colorectal Cancer

PURPOSE Recent literature has shown that lymph node ratio is superior to the absolute number of metastatic lymph nodes in predicting the prognosis in several malignances other than colorectal cancer. The aim of this study was to evaluate the prognostic significance of the lymph node ratio (LNR) in patients with stage III colorectal cancer. METHODS We included 186 stage III colorectal cancer patients who underwent a curative resection over a 10-year period in one hospital. The cutoff point of LNR was chosen as 0.07 because there was significant survival difference at that LNR. The Kaplan-Meier and the Cox proportional hazard models were used to evaluate the prognostic effect according to LNR. RESULTS There was statistically significant longer overall survival in the group of LNR > 0.07 than in the group of LNR ≤ 7 (P = 0.008). Especially, there was a survival difference for the N1 patients group (LN < 4) according to LNR (5-year survival of N1 patients was lower in the group of LNR > 0.07, P = 0.025), but there was no survival difference for the N2 group (4 ≥ LN) according to LNR. The multivariate analysis showed that the LNR is an independent prognostic factor. CONCLUSIONS LNR can be considered as a more accurate and potent modality for prognostic stratifications in patients with stage III colorectal cancer.