Abstract
BACKGROUND: Lung cancer remains a primary contributor to cancer-related mortality globally. Red blood cell distribution width (RDW), a straightforward and cost-effective indicator, measures the variability in red blood cell size and is conventionally employed in hematological assessments for anemia differentiation. Nonetheless, limited research has explored the causal link between RDW levels and lung cancer incidence. METHODS: Initially, Mendelian randomization (MR) was employed to explore the underlying causal connection between RDW and lung cancer. To ensure the robustness of the MR findings, sensitivity analyses were conducted. Following this, the National Health and Nutrition Examination Survey (NHANES) database was utilized to further substantiate the influence of RDW on the prognosis of lung cancer. RESULTS: The MR analysis revealed a significant association between RDW and lung cancer risk in the European population (OR IVW 1.11, 95% CI 1.03-1.20, p = 0.006; OR Weighted-median 1.16, 95% CI 1.03-1.31, p = 0.013; OR MR-Egger 1.14, 95% CI 1.00-1.30, p = 0.059). Furthermore, findings from the NHANES database suggested that lower RDW values are associated with improved prognosis in lung cancer patients (HR 2, 95% CI 1.07-3.74, p < 0.05). CONCLUSIONS: Our study provides further evidence for the relationship between RDW levels and lung cancer, highlighting the potential significance of RDW as a biomarker for predicting lung cancer risk and prognosis.