Effect of Lymph Node Retrieval and Ratio on the Long-Term Survival and Recurrence of Colon Cancer

Objective: To evaluate the association of lymph node retrieval and ratio with the prognosis of colon cancer. Study Design: A cohort study. Place and Duration of Study: Ninewells Hospital and Medical School, Dundee, UK, from October 2014 to March 2015. Methodology: Data was collected for adult patients who were diagnosed with primary adenocarcinoma of colon between 2003 and 2008. The follow-up period was 5-year. The data was collected from regional electronic colorectal cancer database. Kaplan-Meier graph was used to calculate and depict overall survival in different groups of patients. Results: There were a total of 370 patients with colon cancer. For Dukes stages A and B, there was no significant difference in median overall survival for patients with lymph node retrieval (< 12 nodes vs. > 12 nodes). For Dukes stage C (n=147), median survival for patients with lymph node retrieval < 12 nodes was 4 years vs. 4 years for patients with lymph node retrieval > 12 nodes (p = 0.85). Median survival for patients with lymph node ratio (LNR) < 0.125 was 4 years (range 1 - 11) vs. 3 years (range 0 -11) for patients with LNR > 0.125 (p = 0.14). There was no significant difference in the recurrence rate based on lymph node retrieval (p = 0.87) and LNR (p = 0.97). Conclusion: Lymph node retrieval > 12 and reduced LNR < 0.125 had no significant effect on long-term survival and recurrence of colon cancer.