ABSTRACT
BACKGROUND: Increasing evidence has revealed that granulocyte has a critical role in tumorigenesis and progression. In this study, Mendelian randomization (MR) analysis was utilized for estimating the causal association between neutrophil percentage and melanoma skin cancer, eosinophil percentage and melanoma skin cancer, basophil percentage and melanoma skin cancer, respectively. METHODS: The Genome-Wide Association Study (GWAS) ids for melanoma skin cancer, neutrophil percentage, eosinophil percentage and basophil percentage were derived from Integrative Epidemiology Unit (IEU) Open GWAS database. The univariable MR (UVMR) analysis was conducted to estimate the risk using MR-Egger, weighted median, inverse variance weighted (IVW). In addition, sensitivity analysis was conducted to assess the reliability of UVMR results. Finally, the multivariable MR (MVMR) analysis was performed to investigate causality between neutrophil percentage and eosinophil percentage in the presence of both and melanoma skin cancer. RESULTS: The UVMR indicated that neutrophil percentage and eosinophil percentage were significantly and causally related to melanoma skin cancer, with neutrophil percentage [p = 0.025, odds ratio (OR) = 1.002] as a risk factor and eosinophil percentage (p = 7.04E-06, OR = 0.997) as a protective factor. Moreover, MVMR analysis indicated eosinophil percentage remained the protective factor (p = 0.003, OR = 0.998), while the causality of neutrophil percentage and melanoma skin cancer became insignificant (p > 0.05). CONCLUSION: The causal relationships of neutrophil percentage and melanoma skin cancer, eosinophil percentage and melanoma skin cancer were shown by this study, which provided a reference for subsequent research and treatment related to melanoma skin cancer.