Inflammation-Based Prognostication in Advanced-Stage NSCLC: A Retrospective Cohort Study.

: Neutrophil-to-lymphocyte ratio (NLR), a marker of systemic inflammation, has prognostic value in non-small cell lung cancer (NSCLC), but its longitudinal performance in routine care is unclear. We evaluated baseline and 12-month changes in NLR and hemoglobin in a single-center, Eastern European cohort. : In this retrospective study, 180 adults with histologically confirmed NSCLC, diagnosed May 2022-April 2024 at a Romanian tertiary center, were followed until 30 April 2025. Baseline demographics, tumor characteristics, molecular profiles, laboratory parameters, and treatments were extracted from electronic health records. Progression-free survival (PFS) was the primary endpoint, overall survival (OS) the secondary, analyzed using Kaplan-Meier curves and Cox proportional hazards models. An additional treatment-start-anchored sensitivity analysis in treated patients was conducted. : The cohort (median age 67.8 years, 68.9% stage IV) received chemo-immunotherapy (58.9%), immunotherapy (26.7%), chemotherapy (9.4%), or supportive care (5.0%). Median for PFS was 8.2 months and for OS 14.5 months. A high baseline NLR (≥3, 58.9%) increased progression risk (HR 1.60, 95% CI 1.10-2.32, = 0.014), with a trend for worse OS (HR 1.45, 95% CI 0.99-2.12). A 12-month NLR increase (62.2%) further elevated progression risk (HR 1.52, 95% CI 1.05-2.20, = 0.026). Low hemoglobin (<12 g/dL) had a non-significant effect (HR 1.38, 95% CI 0.97-1.96, = 0.074). PD-L1 ≥ 50% and chemo-immunotherapy correlated with longer PFS. Findings were consistent in the treatment-start anchored sensitivity analysis. : These exploratory findings suggest that inexpensive hematologic markers can complement clinical assessment in advanced-stage NSCLC; prospective multi-center validation is warranted.