Neutrophil-Lymphocyte Ratio as a Prognostic Marker for Lung Adenocarcinoma after Complete Resection

Backgrounds: The neutrophil-lymphocyte ratio (NLR) is a simple and low-cost index that may be a benchmark for systemic inflammatory response and antitumor immunity. The goal of the study was to investigate the prognostic value of preoperative NLR in patients with lung adenocarcinoma after complete resection. Methods: The subjects were 361 consecutive patients with lung adenocarcinoma who underwent complete resection between 2000 and 2009. Perioperative clinical and laboratory data were evaluated retrospectively. The cohort was divided using the cut-off value for preoperative NLR identified in receiver operating characteristic analysis. Correlations of NLR with clinicopathological characteristics and prognosis were examined. Results: A high NLR was significantly correlated with a smoking history >10 pack-years (p = 0.023), pathological stage II or III (p < 0.001), lymphatic invasion (p = 0.003), and pleural invasion (p = 0.039). In univariate analysis, the high NLR group had significantly lower 5-year overall survival (86.0 vs. 77.1 %, p < 0.001) and 5-year recurrence-free survival (75.1 vs. 59.9 %, p < 0.001). Multivariate analysis showed that NLR was an independent prognostic factor (hazard ratio 1.822, 95 % confidence interval 1.133-2.931, p = 0.013). Conclusion: These results show that preoperative NLR is an independent prognostic factor in patients with lung adenocarcinoma after complete resection. NLR may reflect host immunity and systemic inflammation that facilitates tumor growth.