Results of a meta-analysis of more that 1.5 million patients do not support the view that statins prevent colorectal cancer.
Some epidemiological and other reports suggest that statins may prevent colorectal cancer. This meta-analysis included randomised controlled trials (RCTs) on cardiovascular outcomes, with data on colorectal cancer as a secondary end point of the published studies.
This meta-analysis included data extracted from six RCTs, nine case control and three cohort studies published up to December 2006, and included more than 1.5 million participants.
The six RCTs included 27,557 patients in treatment groups and 27,556 in control groups, with mean follow-up of 5.9 years. Three reported higher and three reported a lower risk of colorectal cancer, but none were statistically significant. Case control and cohort studies included 1.5 million patients and 38,124 had colorectal cancer.
Results showed no association between statin use and risk of colorectal cancer in the RCTs or the prospective cohort studies. There was a modest reduction in the risk of colorectal cancer in the 9 retrospective case-control studies (RR = 0.91; 95% CI, 0.87 to 0.96).
They noted that the study did not included unpublished or original data. Observational studies may have had unknown social or behavioural factors, as there is evidence that higher socioeconomic classes are more likely to be prescribed statins.
The authors concluded that their results did not support the hypothesis that low dose statins when taken for management of hypercholesterolemia strongly reduce the risk of colorectal cancer, although they could not rule out a modest reduction in risk or an effect associated with higher doses of statins. They noted that the use of statins should remain to be restricted to the approved indications.
Reference
Bonovas, S. Filioussi, K. Flordellis, C. & Sitaras N. 2007, ‘Statins and the risk of colorectal cancer: a meta-analysis of 18 studies involving more than 1.5 million patients,’ Journal of Clinical Oncology, vol. 25, pp. 3462—3468.
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