The association between three prevalent autoimmune disorders and the likelihood of developing prostate cancer: a Mendelian randomization study

Numerous studies establish a significant correlation between autoimmune disorders (AIDs) and prostate cancer (PCa). Our Mendelian randomization (MR) analysis investigates the potential connection between rheumatoid arthritis (RA) and PCa, aiming to confirm causal links between systemic lupus erythematosus (SLE), hyperthyroidism, and PCa. Summary statistics from genome-wide association studies provided data on PCa and three AIDs. MR analysis, using IVW as the main approach, assessed causal relationships, validated by sensitivity analysis. IVW revealed a correlation between genetically anticipated RA and PCa, notably in Europeans (OR = 1.03; 95% CI 1.01-1.04, p = 2*10-5). Evidence supported a lower PCa risk in individuals with SLE (OR = 0.94; 95% CI 0.91-0.97, p = 2*10-4) and hyperthyroidism (OR = 0.02; 95% CI 0.001-0.2, p = 2*10-3). Weighted mode and median confirmed these findings. No pleiotropic effects were observed, and MR heterogeneity tests indicated dataset homogeneity. Our study establishes a causal link between RA, SLE, hyperthyroidism, and PCa.