Two major studies have shown that the cholesterol-lowering drugs called statins do not reduce the risk of colon cancer.
The First Study
One study looked at 27 trials that included nearly 87,000 people. The researchers found that there was no reduced incidence of colorectal cancers (as well as a variety of other cancers) in people who took statins compared with those who did not.
Expectations had been raised by previous studies, one of which found a 47% reduction in colon and rectal cancers in people who took statins for more than five years.
However, those studies "had a lot of methodological flaws," according to C. Michael White, a professor of pharmacology at the University of Connecticut, and the leader of the analysis.
"In our study, we did a meta-analysis of all of the trials, and were not able to show any reduction in cancer or in cancer deaths," White reports.
Most of the people in those trials were taking a single drug, pravastatin (Pravachol), "but when we looked at other statins, we couldn't come up with a mixture that suggested there might be a protective effect," he says.
The Second Study
The second study also found no reduced incidence of colon cancer in the more than 130,000 people who took statins in the Cancer Prevention Study II Nutritional Cohort.
According to the study researchers, "Our results do not support the hypothesis that statins, as a class of drugs, strongly reduce the risk of colorectal cancer."
The two studies are "consistent and complementary," says Eric J. Jacobs, leader of the study as well as an epidemiologist at the American Cancer Society.
"They are consistent in that both show no effect on colon cancer risk. They are complementary in that the meta-analysis was able to look at varieties of statins, whereas our study was able to look at longer-term use," he explains.
The Good News
But the news isn't as bad as it might seem, White says. "The good news is that when statins first came out, people were worried that they might cause cancer," he says. "Now, we know the effect is pretty neutral."
And the reports provide no reason to stop taking statins, White says. "They still do miraculous things for people with heart disease," he says. 'Just don't take them to reduce the risk of cancer. There are other things to do [for that], like not smoking and improvements in diet."
