Metastatic Lymph Node Ratio in Right-Sided Colon Cancers Associated With Decreased Overall Survival

The aim of this study was to investigate the effect of metastatic lymph node ratio (mLNR) on overall survival after curative resection in patients with right-sided colon cancer.

Patients diagnosed with right-sided colon cancer and treated at Istanbul Teaching and Research Hospital between 2012 and 2017 were retrospectively analyzed. Variables including age, sex, total number of lymph nodes removed, metastatic lymph node ratio, disease stage, tumor location, and patient morbidity were compared with overall survival. Kaplan-Meier survival analysis and Cox regression analysis were used to evaluate the impact of these variables on overall survival.

A total of 129 patients were included in this study. By the end of the follow-up period, 51 patients (39.5%) had died. Receiver operating characteristic (ROC) analysis identified a cut-off value for mLNR at 0.0801 (p < 0.001), with 39 patients (30.2%) having an mLNR greater than this threshold. Patients with a high mLNR exhibited significantly shorter overall survival (20.3 months, 95% confidence interval (CI): 12.0-28.6) compared to those with a lower mLNR (106.6 months, 95% CI: 98.4-114.8) (p < 0.001). Furthermore, overall survival was significantly lower in patients with advanced-stage tumors, highlighting the prognostic importance of tumor, node, and metastasis (TNM) staging system. In multivariate Cox regression analysis, TNM stage (hazard ratio (HR) = 50.229, 95% CI: 6.678-372.242, p < 0.001) and mLNR (HR = 3.136, 95% CI: 1.843-5.337, p < 0.001) were identified as independent prognostic factors for overall survival.

This study underscores that in right-sided colon cancer, the mLNR and TNM stage provide critical prognostic insights, independent of the total number of lymph nodes removed. These findings support the use of mLNR as a practical and reliable tool for refining prognostic assessments and guiding personalized treatment strategies, emphasizing its potential role in clinical decision-making.