Abstract / Summary
Background and aim: Lung cancer is frequently associated with systemic inflammation and immune dysregulation, reflected by complete blood count (CBC)-derived indices, including the neutrophil-tolymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR).Eosinophils and basophils are minor leukocyte subpopulations with recognized roles in tumor immunity; however, their associations with classical immune-inflammatory indices remain insufficiently characterized in lung cancer.The aim of this exploratory study was to evaluate associations between absolute eosinophil and basophil counts and CBC-derived immune-inflammatory indices in patients with lung cancer.Materials and methods: We conducted a retrospective cross-sectional observational study in a cohort of 72 patients with primary lung cancer, evaluated before radiotherapy at a tertiary oncology center.A full differential CBC, including absolute eosinophil and basophil counts, was collected, and NLR, MLR, and PLR were calculated.Associations were assessed using Spearman rank correlation coefficients.Multivariable linear regression models with log-transformed dependent variables were constructed, adjusted for active chemotherapy, age, and sex, using HC3 robust standard errors.Results: Eosinophils demonstrated significant inverse correlations with NLR (ρ = -0.295,false discovery rate (FDR)-adjusted p-value (p FDR) = 0.024) and MLR (ρ = -0.346,p FDR=0.012).Basophils were inversely associated with NLR (ρ = -0.336,p FDR=0.012); the association with PLR did not retain significance after FDR correction (ρ = -0.233,p FDR=0.073).In the primary multivariable regression, eosinophils were associated with log(MLR) (β = -0.152,95% CI: -0.250 to -0.053, p=0.004); however, this finding was not robust in sensitivity analyses addressing extreme eosinophil values and distributional skewness.Sensitivity analysis excluding patients on active chemotherapy (n=38) confirmed the eosinophil → NLR association (ρ = -0.448,p=0.005).Conclusions: In lung cancer patients, absolute eosinophil and basophil counts are inversely associated with CBC-derived immune-inflammatory indices.Eosinophils showed an association with MLR in the primary multivariable model, but this finding was not robust across sensitivity analyses.These findings suggest that minor leukocyte subpopulations may contain information about systemic immune-inflammatory status in lung cancer.Prospective studies are needed to clarify the mechanistic and clinical significance of these associations.