Pretreatment and dynamic neutrophil-to-lymphocyte ratio in relation to CT-based volumetric response to platinum-based neoadjuvant chemotherapy in NSCLC

The neutrophil to lymphocyte ratio (NLR) serves as a marker of systemic inflammation and is an established prognostic factor in non-small cell lung cancer (NSCLC). However, its predictive value for treatment response, particularly when evaluated through three-dimensional CT volumetry, remains ambiguous. This study investigates whether pretreatment NLR and treatment-related changes in NLR correlate with volumetric tumor response to platinum-based neoadjuvant chemotherapy (NACT). Adult patients with histologically confirmed NSCLC who received platinum-based NACT and had evaluable pre- and posttreatment CT imaging were included in the analysis. Tumor response was defined as a ≥30% reduction using three-dimensional CT volumetry. We analyzed pretreatment NLR, posttreatment NLR, changes in NLR (ΔNLR), and the NLR ratio. To enhance statistical stability, additional analyses utilized log-transformed NLR values. Associations were examined through non-parametric tests, correlation analysis, and both univariable and multivariable logistic regression models adjusted for age, sex, histology, disease stage, performance status, and baseline tumor volume. A total of 70 patients were included, with 33 (47.1%) achieving a volumetric response. NLR decreased during treatment (median ΔNLR = -0.42), yet no significant differences were noted between responders and non-responders regarding pretreatment NLR (p = 0.773), posttreatment NLR (p = 0.920), ΔNLR (p = 0.514), or NLR ratio (p = 0.630). None of the NLR-derived parameters showed significant associations with treatment response in univariable or multivariable models, including those utilizing log-transformed variables. Furthermore, the NLR ratio exhibited substantial instability, reflected in wide confidence intervals. In conclusion, within this cohort, neither pretreatment nor dynamic NLR parameters were significantly associated with CT-based volumetric tumor response following platinum-based NACT.