Metastatic non-small cell lung cancer (NSCLC) represents one of the biggest therapeutic challenges. Palliative chemotherapy (CT) is the first-choice treatment in patients without targetable mutations. Unfortunately, reliable markers predicting response to CT have not been found yet. Most of NSCLC cases arise and develop in a background of smoking-related chronic inflammation. Since neutrophils are the most prevalent immune cell type in NSCLC microenvironment we hypothesized that the revelator of the inflammatory process such as the neutrophil to lymphocyte ratio (NLR) could have a prognostic or predictive value.
To evaluate the predictive and prognostic value of pretreatment NLR in NSCLC we analyzed data of the group of consecutive patients treated systemically for NSCLC at two institutions between January 2011 and December 2014. NLR was retrospectively calculated from the peripheral blood counts collected before therapy. Multivariate Cox logistic regression was used to assess the relationship between NLR and treatment results after adjusting for age, gender, ECOG, and cigarette smoking. Based on available data we chose NLR=3 as the cut-off level discriminating high (NLR >3) and low values.
In the whole cohort (N = 204) with 184 patients (90%) being current or former smokers, 131 (64%) were male, 188 (92%) had a performance status (PS) 0 to 1, 93 patients (46%) had squamous cell cancer, 85 (42%) adenocarcinoma, and 26 (12%) other subtypes. Median age at diagnosis was 65 years (range 41 to 71.7 years). Platinum-based CT was administered in 92% of patients: cisplatin in 155 (76%), and carboplatin in 33 (16%) patients. NLR ranged from 2.04 to 4.62 (median = 3.02). Study groups created according to the NLR value were well balanced. There were 54 objective responses (26,5%) including 2 complete remissions. NLR was a significant and independent factor predicting response to treatment (OR 0.048; 95% CI 0.015-0.152; p < 0.001). Median overall survival in all patients was 12 months: 9.6 vs 13.2 months, respectively in NLR>3 vs ≤ 3 (p < 0.001).
NLR>3 was correlated with worse outcomes, therefore might be useful for identifying patients unlikely to benefit from CT.
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