Combination of the Ratio Between Negative and Harvested Lymph Nodes and Metastatic Lymph Node Count as a Prognostic Indicator in Stage III Colon Cancer: A Retrospective Cohort Study

Background This study aimed to investigate the relationship between the ratio of negative lymph nodes (NLN) number to the number of metastatic lymph nodes (MLN) and the harvested lymph nodes (HLN) number ratio survival rate and compare its prognostic value. Methods This retrospective cohort study included 207 stage III colon cancer patients between 2010 and 2018 at a single center. NLN/MLN and NLN/HLN cut-off values were determined with the receiver operating characteristic (ROC) curve according to 5-year survival. The patients were divided into high-risk and low-risk groups according to the cut-off value. These 2 groups were evaluated according to the clinicopathological data of the patients. Result The time-dependent ROC curve showed the optimal cut-off values of NLN as 3.86 and .79, respectively. These values show 83 patients in the high-risk group and 124 in the low-risk group. There was no difference between the groups in tumor localization and T stage. According to Kaplan-Meier survival analysis, mean survival was 35.88 months in the high-risk group and 50.18 months in the low-risk group. The risk of death in the high-risk group was 305% compared to the low-risk group (Hazard Ratio: 3.05, 95% 1.91 - 4.88) (P < .001). Conclusion NLNs are among the critical prognostic factors in colon cancer. Although NLNs have a positive correlation with the survival rate of the patients, there is no statistical difference in tumor T stage and localization.