Background: The immune system has been shown to play an important role in preventing cancer progression. The neutrophil-lymphocyte ratio (NLR) has been proposed to be an indicator of a systemic inflammatory response. We investigated the prognostic significance of NLR in patients with completely resected stage I non-small lung cancer (NSCLC).
Methods: A series of 343 pathological stage I NSCLC patients, completely resected between 2000 and 2008 at a single institution, were evaluated retrospectively. Perioperative clinical and laboratory data were collected, and the cohort was divided into two groups according to preoperative NLR. We examined the correlation between NLR and clinicopathological parameters and determined the prognostic significance.
Results: High NLR was significantly correlated with patients of older age (p = 0.045), preoperative hypoalbuminemia (p = 0.030), and nonadenocarcinoma histology (p = 0.045). Upon univariate analysis, the high NLR group had significantly lower 5-year recurrence-free survival (81.2 vs. 59.9 %, p < 0.001) and 5-year overall survival (89.2 vs. 72.8 %, p < 0.001) than the low NLR group. Multivariate analysis showed that NLR was an independent prognostic factor (hazard ratio 2.141, 95 % confidence interval; 1.306-3.515, p = 0.003). In terms of initial recurrent sites, the proportion of patients who developed distant metastasis was significantly higher in the high NLR group than in the low NLR group (p < 0.001).
Conclusions: Preoperative high NLR is a significant predictor of poor prognosis and is associated with more frequent distant metastasis in patients with completely resected stage I NSCLC. This readily available and simply calculated ratio provides useful information for the clinician to consider in terms of perioperative management.