Statins and the risk of colorectal cancer; a systematic review and meta-analysis of cohort and case-control studies

Introduction: Colorectal malignancy is the third furthermost frequent malignancy in the world, and approximately 80% of the cases are related to nongenetic causes, including high cholesterol levels. Accordingly, the present systematic review and meta-analysis aimed to investigate the relationship between statin treatment and the risk of colorectal cancer. Materials and Methods: The current study was a systematic review and meta-analysis designed based on PRISMA. International databases, including PubMed, Scopus, Web of Science, Cochrane, and Google Scholar search engine, were used to search for studies published until July 7, 2023. Data analysis was directed by STATA software version 14, and P values below than 0.05 (P<0.05) indicated the significance of statistical tests. Results: The results obtained from a combination of 30 studies with 2436650 samples indicated that statin use increased the risk of colorectal malignancy by 11% (OR: 0.89; 95% CI: 0.84, 0.95) and reduced the risk of rectal cancer by 16% (R: 0.84; 95% CI: 0.74, 0.94). Instead, statin administration reduced the hazard of colorectal cancer in individuals aged 50 to 59 by 22% (R: 0.78; 95% CI: 0.63, 0.95), 60 to 69 by 14% (OR: 0.86; 95% CI: 0.75, 0.98), and 70 to 79 by 8% (OR: 0.92; 95% CI: 0.87, 0.98). Utilization of statin in male (OR: 0.71; 95% CI: 0.58, 0.87) and female (OR: 0.84; 95% CI: 0.77, 0.92) patients reduced the risk of colorectal cancer by 29% and 16%, respectively. Furthermore, statin use in men (OR: 0.41; 95% CI: 0.26, 0.67) and women (OR: 0.64; 95% CI: 0.42, 0.97) reduced the risk of colon cancer by 59% and 36%, respectively. Conclusion: Statin administration reduced the risk of colorectal cancer, and the possibility of reduction in risk of colorectal cancer at lower ages was higher than in older adults and also higher in males compared with females. Registration: This study has been compiled based on the PRISMA checklist, and its protocol was registered on the PROSPERO (CRD42023450984) and Research Registry (UIN: reviewregistry1779) website.