Pretreatment neutrophil-to-lymphocyte ratio predicts treatment efficacy and prognosis of cytotoxic anticancer drugs, molecular targeted drugs, and immune checkpoint inhibitors in patients with advanced non-small cell lung cancer

Background: Neutrophil-to-lymphocyte ratio (NLR) has recently attracted attention as a prognostic predictor in patients with non-small cell lung cancer (NSCLC) who receive immune checkpoint inhibitors (ICIs). However, the utility of NLR in relation to cytotoxic anticancer drugs or molecular targeted drugs remains unclear. We determined if NLR could predict the treatment efficacy and prognosis in NSCLC patients who receive cytotoxic anticancer drugs or molecular targeted drugs, as well as ICIs, in a cross-sectional manner. Methods: Of 658 patients with advanced NSCLC who received first-line systemic treatment in our hospital between 2008 and 2019, 312 who met the analytical criteria were included in the study. We retrospectively analyzed the ability of NLR with a cut-off value of 5 to predict time to treatment failure (TTF) and overall survival (OS) in patients who received the following treatments: first-line treatment with molecular targeted drugs (mt group, n=100); first-line treatment with cytotoxic anticancer drugs (wt group, n=212); and first-line treatment with cytotoxic anticancer drugs followed by ICIs (ICI group, n=58). Results: In the high- and low-NLR mt subgroups, median TTFs were 6.7 and 14.9 months (P<0.01), respectively, and median survival times (MSTs) were 17.8 and 39.1 months (P<0.01), respectively. In the high- and low-NLR wt subgroups, median TTFs were 1.5 and 5.8 months (P<0.01), and MSTs were 6.3 and 20.7 months (P<0.01), respectively. In the high- and low-NLR ICI subgroups, median TTFs were 1.3 and 6.8 months (P<0.01), and MSTs were 9.2 and 25.8 months (P<0.01), respectively. Multivariate analysis identified NLR as a significant independent predictor of TTF [hazard ratio (HR) 1.89, P=0.01; HR 2.51, P<0.01; and HR 5.06, P<0.01 in the mt, wt, and ICI groups, respectively) and OS (HR 3.81, P<0.01; HR 2.59, P<0.01; and HR 2.48, P<0.01, respectively). Conclusions: This study showed that NLR might be a predictor of treatment efficacy and prognosis in advanced NSCLC patients who receive various systemic treatments. This finding of consistent applicability of NLR to a wide variety of systemic treatments is of great significance.