Statin use and the risk of multiple myeloma: a PRISMA-compliant meta-analysis

Previous studies exploring associations between statin use and risk of multiple myeloma (MM) showed inconsistent results. We searched for articles published in English in databases (PubMed, Web of Science, EMBASE, Medline, and Google Scholar) before October 2019. The multivariate odds ratio (OR)/relative risk (RR) and 95% confidence intervals (CI) were computed to explore associations between statin use and risk of MM. The study indicated that statin users showed significantly lower risks of MM with a random effects model (OR/RR = 0.77, 95% CI 0.63 to 0.95, I² = 63.1%, p for Q test = 0.001). Subgroup analyses showed that statin users showed significantly lower risks of MM in Caucasian populations with a fixed effects model (OR/RR = 0.72, 95% CI 0.59 to 0.88, I² = 43.5%, p for Q test = 0.060), whereas no significant association was shown between statin use and risks of MM in Asian populations with a random effects model. Additionally, Subgroup analyses showed that statin users showed significantly lower risks of MM in cohort studies with a fixed effects model (RR = 0.83, 95% CI 0.74 to 0.93, I² = 0.0%, p for Q test = 0.429), whereas no significant association was shown between statin use and risks of MM in case-control studies with a random effects model. In conclusion, the present study indicated that statin use might be a protective factor for MM incidence. However, the relationship between statin use and MM risk requires repeated and large prospective studies to be verified.