Prognostic impact of circulating monocytes and lymphocyte-to-monocyte ratio on previously untreated metastatic non-small cell lung cancer patients receiving platinum-based doublet

The link between circulating lymphocyte-to-monocyte ratio (LMR) and newly diagnosed metastatic non-small cell lung cancer (NSCLC) is not fully defined. The study was conducted to evaluate the prognostic impact of LMR on survival outcomes in previously untreated metastatic NSCLC patients receiving platinum-based doublet. Chemotherapy-naive metastatic NSCLC patients undergoing platinum-based doublet were retrospectively enrolled. Clinical features regarding gender, age, Eastern Cooperative Oncology Group (ECOG) performance status, histology, absolute lymphocyte count (ALC), absolute monocyte count (AMC) and LMR were collected to determinate their prognostic impact on progression-free survival (PFS) and overall survival (OS). Up to 370 patients were eligible for the study. By univariate analysis, ECOG performance status, histology, ALC, AMC and LMR were showed to be significantly associated with PFS and OS. In subsequent Cox multivariate analysis, non-squamous cell carcinoma, ALC ≥2.45 × 10⁹/L, AMC <0.45 × 10⁹/L and LMR ≥4.56 were demonstrated to be independently correlated with better PFS. In addition, independent favorable prognostic factors for OS were only limited to LMR ≥4.56 and non-squamous cell carcinoma, whereas ECOG performance status of 2 and AMC ≥0.45 × 10⁹/L remained as independently inferior prognostic indicators for OS. Our findings implicate that circulating AMC and LMR are regarded as independent prognostic factors for PFS and OS in previously untreated metastatic NSCLC patients receiving platinum-based doublet.