Impact of Lymph Node Ratio as a Prognostic Factor for Survival in Colorectal Cancer Patients

Aim: The aim of this study was to investigate the impact of the ratio of metastatic lymph nodes to total harvested lymph nodes on survival rates. Method: Data from patients with colorectal cancer undergoing surgery in Ankara Numune Training and Research Hospital, Clinic of General Surgery between June 2010 and June 2015 was retrospectively analyzed. We gathered data about patients’ age, gender, operational status (elective or emergency), operation format (with laparotomy or laparoscopic), performed procedures, localization of the tumor, TNM stage, Dukes’ stage, adjuvant/neoadjuvant chemoradiotherapy history, harvested lymph nodes, lymph node ratio (LNR) and overall survival. We conducted univariant and multivariant analyses to determine the relation between LNR and survival. Results: Forty-five patients were excluded, resulting in a study cohort of 391 patients with a mean age of 62.7±13.7 years, of whom 234 (59.8%) were male. Based on the results of univariant analysis, the cut-off values for LNR 0.2 and 0.5 showed a significant association with survival (LNR: 0.2 p<0.05 and LNR: 0.5 p<0.05). These LNR values maintained a significant relationship with survival after multivariant analysis (LNR: 0.2 p<0.05 and LNR: 0.5 p<0.05). Conclusion: In this retrospective study LNR was a significant prognostic factor for survival in patints undergoing surgery for colorectal cancer. To determine the prognosis of the patients with suboptimal lymph node yield and decide the adjuvant therapy choices, LNR can be used as a helpful indicator with the total number of harvested lymph nodes and the number of positive lymph nodes.