Neutrophil to lymphocyte ratio (NLR) as an indicator of poor prognosis in stage IV non-small cell lung cancer.

BACKGROUND: Neutrophil to lymphocyte ratio (NLR), an index of systemic inflammation, has been associated with worse survival for many types of cancer. The aim of this study is to investigate the clinical significance of the blood NLR as a prognostic factor in non-small cell lung cancer (NSCLC) patients.

METHODS AND PATIENTS: Stage IV NSCLC patients diagnosed in our institution between April 2004 and March 2009 were retrospectively reviewed. Potential prognostic factors such as histology, gender, performance status, response to chemotherapy and NLR were analyzed. NLR was assessed baseline and during chemotherapy treatment. Overall survival (OS) and progression free survival (PFS) were calculated by the Kaplan-Meier method.

RESULTS: A total of 171 patients were included in the study and 60 patients (35.1 %) presented a NLR ≥ 5. Median survival for the entire cohort was 9.3 months. We found that patients with undifferentiated carcinoma and patients with NLR ≥ 5 had a worse survival. Median PFS of patients with NLR <5 was 5.62 months and in patients with NLR ≥ 5 was 3.25 months (p = 0.098), and OS was 11.1 versus 5.6 months for patients with NLR<5 and NLR ≥ 5, respectively (p = 0.017). During the chemotherapy treatment, patients who normalized NLR after one cycle presented better outcomes (OS 8.7 vs. 4.3 months, p = 0.001, for patients who normalized NLR and for patients who remained persistently elevated). After multivariate analysis, histology and NLR remained independent predictors of survival (p < 0.05).

CONCLUSION: In our analysis, elevated NLR is a predictor of shorter survival in patients with advanced NSCLC and the variation of NLR during the first cycle of treatment predicts survival. NLR is an easily measured, reproducible test that could be considered to be incorporated in the routine practice in NSCLC patients.