Taking statin drugs may lower the risk of colon cancer by 12%, according to a meta-analysis covering over 2.5 million people.

The review, presented at the American College of Gastroenterology meeting in San Antonio, USA, was carried out by investigators at the University of Michigan at Ann Arbor, included 22 scientific studies. Jewel Samadder, who led the analysis, noted that statin use was associated with a statistically significant reduction in colorectal cancer," ie 12%, and this effect was "largely consistent across study design with both case control and cohort studies showing a strong correlation".

He added that the length of statin use, both greater than six months and more than five years of use was associated with reduction in colorectal cancer risk. Dr Samadder went on to say that importantly, when the analysis was stratified for statin type, lipophilic drugs - such as Pfizer's Lipitor (atorvastatin) and Merck & Co's now off-patent Zocor (simvastatin) - showed the greatest effect.

Dr Samadder noted that observational studies have suggested that long_term use of statins is associated with reduced risk of several cancers, including breast, prostate, lung, pancreas and liver. "Our findings suggest that randomised controlled trials designed to test the hypothesis that statins reduce the risk of colorectal cancer are warranted," he concluded.