Statin use may significantly lower the risk of colorectal cancer (CRC) in patients with or without inflammatory bowel disease (IBD), based on a meta-analysis and systematic review.
In more than 15,000 patients with IBD, statin use was associated with a 60% reduced risk of CRC, reported lead author Kevin N. Singh, MD, of NYU Langone Medical Center in New York, and colleagues.
“Statin use has been linked with a risk reduction for cancers including hepatocellular carcinoma, breast, gastric, pancreatic, and biliary tract cancers, but data supporting the use of statins for chemoprevention against CRC is conflicting,” Dr. Singh said during a virtual presentation at the annual meeting of the American College of Gastroenterology.
He noted a 2014 meta-analysis by Lytras and colleagues that reported a 9% CRC risk reduction in statin users who did not have IBD. In patients with IBD, data are scarce, according to Dr. Singh.
To further explore the relationship between statin use and CRC in patients without IBD, the investigators analyzed data from 52 studies, including 8 randomized clinical trials, 17 cohort studies, and 27 case-control studies. Of the 11,459,306 patients involved, approximately 2 million used statins and roughly 9 million did not.
To evaluate the same relationship in patients with IBD, the investigators conducted a separate meta-analysis involving 15,342 patients from 5 observational studies, 1 of which was an unpublished abstract. In the 4 published studies, 1,161 patients used statins while 12,145 did not.
In the non-IBD population, statin use was associated with a 20% reduced risk of CRC (pooled odds ratio, 0.80; 95% confidence interval, 0.73-0.88; P less than .001). In patients with IBD, statin use was associated with a 60% CRC risk reduction (pooled OR, 0.40; 95% CI, 0.19-0.86, P = .019).
Dr. Singh noted “significant heterogeneity” in both analyses (I2 greater than 75), most prominently in the IBD populations, which he ascribed to “differences in demographic features, ethnic groups, and risk factors for CRC.”
While publication bias was absent from the non-IBD analysis, it was detected in the IBD portion of the study. Dr. Singh said that selection bias may also have been present in the IBD analysis, due to exclusive use of observational studies.
“Prospective trials are needed to confirm the risk reduction of CRC in the IBD population, including whether the effects of statins differ between ulcerative colitis and Crohn’s disease patients,” Dr. Singh said.
Additional analyses are underway, he added, including one that will account for the potentially confounding effect of aspirin use.
According to David E. Kaplan, MD, of the University of Pennsylvania, Philadelphia, “The finding that statins are associated with reduced CRC in IBD provides additional support for the clinical importance of the antineoplastic effects of statins. This effect has been strongly observed in liver cancer, and is pending prospective validation.”
Dr. Kaplan also offered some mechanistic insight into why statins have an anticancer effect, pointing to “the centrality of cholesterol biosynthesis for development and/or progression of malignancy.”
The investigators and Dr. Kaplan reported no relevant conflicts of interest.