Prognostic Value of the Preoperative Lymphocyte-to-monocyte Ratio for Survival After Lung Cancer Surgery

BACKGROUND The aim of this study was to assess the effect of the lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio on overall survival and disease-free survival in patients with lung cancer treated with radical surgery. METHODS We performed a retrospective review of patients with lung cancer who prospectively underwent radical resection between 2004 and 2012. Blood samples were taken as part of the preoperative workup. The inflammatory markers studied were absolute values of lymphocytes, monocytes, neutrophils and platelets, with subsequent calculation of ratios. Median follow-up was 52 months. RESULTS Two hundred and sixty-eight patients underwent surgery, of whom 218 (81.3%) were men. Mean age was 62.9 ± 8.7 years. A lymphocyte-to-monocyte ratio ≥ 2.5 was independently associated with longer disease-free survival (hazard ratio [HR] 0.476 (0.307-0.738), p = 0.001) and longer overall survival (HR, 0.546; 95% CI: 0.352-0.846; p = 0.007), in models adjusted for age, sex, stage, and type of resection. No other systemic inflammatory marker showed a significant association. CONCLUSION Preoperative LMR is an independent prognostic factor of overall survival and recurrence-free survival in patients with surgically-resected early stage lung cancer.