Prognostic role of neutrophil–lymphocyte ratio in multiple myeloma: a dose–response meta-analysis

BACKGROUND: The neutrophil–lymphocyte ratio (NLR), a biomarker for systematic inflammation, has been recently identified as a prognostic factor for various types of both solid and hematologic malignancies. Our study presented here was the first meta-analysis assessing the prognostic role of NLR in multiple myeloma (MM). METHODS: We systematically searched PubMed, Embase, and ISI Web of Science for relevant studies. Odds ratios (ORs) or hazards ratios (HRs) with corresponding 95% CIs are pooled to estimate the association between NLR and clinicopathological parameters or survival of MM patients. RESULTS: Seven trials with 1,971 MM patients were enrolled in the meta-analysis, and the results indicated that elevated pretreatment NLR was significantly associated with advanced tumor stages (International Staging System [ISS] III vs ISS I–II: OR 2.427, 95% CI: 1.268–4.467; and Durie–Salmon III vs Durie–Salmon I–II: OR 1.738, 95% CI: 1.133–2.665). Moreover, increased NLR also predicted poorer overall survival (HR 2.084, 95% CI: 1.341–3.238) and progression-free survival (HR 1.029, 95% CI: 1.016–1.042). And two-stage dose–response meta-analysis revealed linear association between increased NLR and risk of mortality in MM patients. CONCLUSION: We can conclude that MM patients with higher NLR are more likely to have poorer prognosis than those with lower NLR.