目前尚不清楚类风湿性关节炎（RA）与前列腺癌（Pca）之间的关联是否存在因果关系。我们进行了一项荟萃分析，并利用Mendelian随机化方法（MR）评估了RA与Pca风险之间的关联。我们进行了Pca发病率的荟萃分析和亚组分析，研究RA患者中Pca的发生率。为了确定遗传上升的RA水平是否与Pca有因果关联，我们使用了两个MR样本。为了消除与性别相关的偏差，我们对包括140,254名男性在内的RA GWAS数据进行了分层分析。我们还进行了额外的MR分析，以确定影响遗传易感RA与Pca关联的混杂因素。总共有409,950名参与者参加了20项试验，调查了RA患者的Pca风险。荟萃分析表明RA与Pca风险无关（SIR = 1.072, 95% CI，0.883-1.261）。然而，亚组分析显示在RA患者中，低吸烟率可能会增加Pca风险24%。MR分析表明遗传易感RA与高Pca风险有关（OR = 36.20，95%CI = 1.24-1053.12，P = 0.037）。MR-Egger、Weighted mode、Simple mode和Weighted median方法的因果估计结果在方向和大小上基本一致。尽管我们的荟萃分析未发现RA与Pca风险之间的相关性，但MR分析支持遗传易感RA与增加的前列腺风险之间存在因果关系。对RA患者的早期关注Pca风险可能对改善患者预后和死亡率很重要。需要进一步研究以确定与Pca相关的RA的病因和潜在机制。 © 2023年。作者，Springer Nature Switzerland AG独家许可。

It is unclear if the association between rheumatoid arthritis (RA) and a higher risk of prostate cancer (Pca) reflects a causal relationship. We conducted a meta-analysis and used the Mendelian randomization method (MR) to evaluate the association between RA and Pca risk. A meta-analysis and subgroup analysis of the incidence of Pca in patients with RA was conducted. To determine whether genetically elevated RA levels were causally linked to Pca, two MR samples were employed. To eliminate gender-related bias, we conducted a stratified analysis of the GWAS data for RA by gender, specifically including 140,254 males. Additional MR analysis was also performed to determine potential confounding factors influencing the association between genetically susceptible RA and Pca. In total, 409,950 participants were enrolled in 20 trials to investigate the Pca risk in patients with RA. The meta-analysis suggested that RA was unrelated to the Pca risk (SIR = 1.072, 95% CI, 0.883-1.261). However, a subgroup analysis showed that low smoking rates might increase the Pca risk in patients with RA by 24%. The MR analysis showed that increased genetic susceptibility to RA was related to a high Pca risk (OR = 36.20, 95%CI = 1.24-1053.12, P = 0.037). The causality estimation of MR-Egger, Weighted mode, Simple mode, and Weighted median method were similar in direction and magnitude. Although our meta-analysis found no correlation between RA and Pca risk, MR analyses supported a causal relationship between genetic susceptibility to RA and increased prostate risk. Early attention to Pca risk in patients with RA may be important for improving prognosis and mortality in such patients. Further research is needed to determine the etiology of RA attributed to Pca and its underlying mechanisms.© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.