Peripheral Neutrophil to Lymphocyte Ratio Improves Prognostication in Colon Cancer

Background: We studied the role of peripheral neutrophil to lymphocyte ratio (NLR) on survival outcomes in colon and rectal cancer to determine if its inclusion improved prognostication within existing staging systems. Patients and Methods: Disease-free (DFS) and overall survival (OS) hazard ratios (HRs) of pretreatment NLR were calculated for 2536 patients with stage I to III colon or rectal cancer and adjusted for age, positive/total number of nodes, T stage, and grade. The association of NLR with clinicopathologic features and survival was evaluated and compared with the American Joint Committee on cancer (AJCC) TNM staging and Memorial Sloan Kettering Cancer Center (MSKCC) models. Results: High NLR was significantly associated with worse DFS (HR, 1.36; 95% confidence interval [CI], 1.08-1.70; P = .009) and OS (HR, 1.65; 95% CI, 1.29-2.10; P < .0005) in all stages for patients with colon, but not rectal, cancer. High NLR was significantly associated with site-specific worse prognosis, which was stronger in the left versus right colon; an inverse relationship with grade was found. The impact of high NLR on DFS and OS occurred early, with the majority of deaths within 2 years following surgery. Adjusted HRs for 5-year and 2-year outcomes in colon cancer per each additional 2-unit increase in NLR were 1.15 (95% CI, 1.08-1.23) and 1.20 (95% CI, 1.10-1.30), respectively. The addition of NLR enhanced the prognostic utility of TNM (TNM alone vs. TNM + NLR: concordance index, 0.60 vs. 0.68), and MSKCC (MSKCC alone vs. MSKCC + NLR: concordance index, 0.71 vs. 0.73) models for colon cancer patients. Conclusion: NLR is an independent prognostic variable for nonmetastatic colon cancer that enhances existing clinical staging systems.