Introduction: Colon cancer is one of the most common malignancies accounting to the 4th most frequent cancer in men and 3rd in women. Though the most commonly used system for cancer staging is TNM classification, it has some prognostic limitations in stage III disease. Node related factors that are of prognostic interest include lymph node size, distribution as well as the lymph node ratio (LNR) which is the quota between positive and total assessed lymph nodes. Aim and objectives: The aim of this study was to evaluate and to describe the lymph node ratio as a prognostic parameter for patients with stage III colon cancer by assessing disease free survival period. Methods: The study is retrospective and included all the patients diagnosed with stage III colon cancer during 2010 to 2014. LNR was calculated and quartile groups were created. LNR and associated parameters were analyzed with reference to disease-free survival (DFS) by follow up of these patients. Results: The Karl Pearson’s correlation analyses was used to determine the correlation coefficient, the Kaplan Meier method was used to analyze survival and the Cox proportional hazard regression model was used for multivariate analysis. The results showed that the lymph node ratio was a prognostic factor in stage III colorectal cancer and had a better prognostic value than did N stage of TNM classification. Conclusion: The lymph node ratio, that is the quota between the number of metastatic lymphnodes and total assessed lymph nodes proved to be a significant prognostic factor in stage III colon cancer as is determined by disease free survival time during follow up of the patients.

Keywords: Colon Cancer; Disease Free Survival; Lymph Node Ratio; Prognostic Parameter.