Investigating bidirectional causality between prostate cancer and inflammatory factors: A 2-sample Mendelian randomization analysis.

Growing evidence have indicated the bidirectional relationships between various inflammatory cytokines and prostate cancer (PCa), but the causality between genetic susceptibility to inflammatory cytokines and PCa was still in initial exploratory phase. This bidirectional Mendelian randomization (MR) research was manipulated to draw causative inferences and the effect of direction between 91 inflammatory cytokines and PCa. Genetic data of PCa were originated from a publicly accessible genome-wide association study with 3269 individuals and 459,664 controls, and inflammatory cytokines summarized by a protein quantitative trait locus study were embodied 14,824 participants. We considered inverse variance weighted as a primarily statistical approach, and utilized MR-Egger regression, weighted median, MR-PRESSO, and simulation extrapolation method to enhance the accuracy of the ultimate outcome. In sensitivity analysis, MR-Egger method and Cochran Q statistic of inverse variance weighted were employed to access the heterogeneity. The results suggested a causal relationship between fms-related tyrosine kinase 3 ligand (Flt3L), recombinant monocyte chemotactic protein (MCP) 2, MCP4, and the incidence of PCa (odds ratio [OR]: 1.0016, 95% confidence interval [CI]: 1.0000-1.0032, P = .045; OR: 0.9979, 95% CI: 0.9958-1.0000, P = .045; OR: 1.0012, 95% CI: 1.0001-1.0023, P = .031). In addition, reverse analysis showed that PCa was correlated with the elevated level of adenosine deaminase, axin-1, C-X-C motif chemokine ligand 6, Flt3L, interleukin (IL)-24, and IL-33 (Beta: 1.7661, 95% CI: 0.2092-3.3229, P = .026; Beta: 1.9185, 95% CI: 0.1548-3.6822, P = .033; Beta: 1.9681, 95% CI: 0.4207-3.5155, P = .013; Beta: 1.6589, 95% CI: 0.0733-3.2446, P = .040; Beta: 2.2091, 95% CI: 0.4682-3.9500, P = .013; Beta: 1.8438, 95% CI: 0.0815-3.6061, P = 040). This study highlighted the causality between several inflammatory factors and the setting of PCa. Specifically, the results suggested that Flt3L and MCP4 may be risk factors for PCa, whereas MCP2 may be a favorable factor for PCa. Conversely, adenosine deaminase, axin-1, C-X-C motif chemokine ligand 6, IL-24, IL-33, and Flt3L were involved in the downstream of PCa progression.