Prognostic Significance of Peripheral Blood Neutrophil‐To‐Lymphocyte Ratio ( <scp>NLR</scp> ), Monocyte‐To‐Lymphocyte Ratio ( <scp>MLR</scp> ), and Platelet‐To‐Lymphocyte Ratio ( <scp>PLR</scp> ) in Patients With Multiple Myeloma: A Retrospective Coh

BACKGROUND: The tumor microenvironment drives pathogenesis and drug resistance in multiple myeloma (MM), while the R-ISS does not capture host immune status. We investigated whether simple systemic inflammation markers-neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, and platelet-to-lymphocyte ratio-could improve prognostic assessment and identify high-risk patients among newly diagnosed MM patients treated with novel agents in a retrospective cohort. METHODS: We conducted a single-center retrospective analysis of 268 newly diagnosed MM patients between January 2019 and December 2023. Optimal cut-off values were determined using Receiver Operating Characteristic (ROC) curve analysis. The primary endpoints were Overall Survival (OS) and Progression-Free Survival (PFS). RESULTS: The optimal cut-off values were determined as 2.85 for NLR, 0.34 for MLR, and 142.5 for PLR. Elevated NLR and MLR were significantly correlated with advanced R-ISS stage (III), anemia, and high beta-2 microglobulin (p < 0.01). Kaplan-Meier analysis showed that patients with high NLR and MLR had significantly inferior OS and PFS. In the multivariate Cox regression model adjusted for cytogenetic risk and post-induction ASCT, high NLR (HR = 1.84, 95% CI: 1.22-2.78, p = 0.004) and high MLR (HR = 1.65, 95% CI: 1.10-2.48, p = 0.015) remained independent prognostic factors. PLR was not significant in multivariate analysis. CONCLUSION: Pretreatment NLR and MLR are robust, cost-effective prognostic biomarkers in MM that retain their independent predictive value even after adjusting for the R-ISS and intensive post-induction therapies such as ASCT. They reflect the immunosuppressive TME and may significantly refine the current staging system to identify high-risk patients who might require earlier immune-bridging interventions.