What is the impact of the Lymph Node Ratio (LNR) on Overall Survival (OS) in patients with colon cancer?

Introduction: Colorectal cancer (CRC) is a major health concern globally, with lymph node metastasis being a key factor in its spread. The Lymph Node Ratio (LNR) – the ratio of pathologically positive lymph nodes to the total number of examined nodes – has emerged as a significant prognostic factor in CRC. Notably, there is a lack of data from prospective cohort studies on this topic. This study aims to investigate the impact of LNR on Overall Survival (OS) in patients with colon cancer, expanding the knowledge on its prognostic value beyond current AJCC TNM classification. Materials and Methods A prospective cohort study was conducted across seven Polish surgical centers enrolling 445 patients with primary colon cancer. The study collected survival data until September 30, 2022, focusing on patients aged 18–75 years eligible for radical surgery. Preoperative assessments included demographic information, Body Mass Index (BMI) and histopathological evaluation according to AJCC 8th edition. Surgical complications were graded using the Clavien-Dindo scale. The relationship between OS and LNR was analyzed using a multivariate Cox proportional hazards model, adjusting for significant covariates. Results In the multivariate Cox model, LNR, BMI and grade III or higher surgical complications were independently associated with overall survival in colon cancer patients. For LNR, a 0.1-unit increase was associated with a 26% increase in the hazard of death over the whole observation period (95% CI: 7–48% increase, p = 0.006). Conclusion LNR, along with BMI and the severity of postoperative complications, serves as an independent prognostic factor for OS in colon cancer patients. These results of prospective cohort study support the inclusion of LNR in future oncological staging systems and highlight the importance of comprehensive lymph node analysis in managing colon cancer.