June 2, 2003 (Chicago) -- Dutch cancer researchers report that the popular cholesterol-lowering drugs called statins, already well known for their ability to reduce risk of heart attack, can reduce the risk of cancer by as much as 36% if taken for at least four years.
Statins offer the most protection against prostate and kidney cancer, Matthijs Graaf, PharmD, at the University of Amsterdam, tells WebMD. He says that no benefit was seen for breast, lung, or colon cancer or for cancers of the blood.
"Overall, taking statins reduces risk of developing cancer by 20%, but that protection increases to 36% for people who take statins for four years or more," Graaf says.
"But the benefit stops about six months after the patient stops taking the drug," he says.
Graaf, who presented the study at the 39th annual meeting of the American Society of Clinical Oncology, says statins lower cholesterol and prevent cancer in much the same way. Statins lower cholesterol by shutting down an enzyme called HMG-CoA reductase. He says this same enzyme also regulates cell growth. Shutting down the enzyme with statin treatment appears to prevent the uncontrolled cell growth that causes cancer.
In the study, Graaf's team identified more than 3,200 cancer patients among people with heart disease. They compared them with more than 16,000 heart disease patients who didn't develop cancer.
Patients who had taken at least 1,350 daily doses of a statin -- just under four years of treatment -- reduced their risk of all types of cancer by 40% compared with patients who didn't take statins. The researchers corrected for other cholesterol-lowering treatments as well as for other medications including high blood pressure medicines, anti-inflammatory drugs, aspirin, and estrogen -- just in case any of these drugs have some effect on cancer prevention.
When Graaf and his colleagues delved deeper into their study results, they found that the cancer prevention was significant only for prostate and kidney cancers.
In the study, about 80% of the patients taking statins were taking Zocor, says Graaf. But he says he suspects that all the statins would have a similar effect. However, he adds that this study really only supports this finding for Zocor.
He says, too, that the study is limited because he and his colleagues didn't consider other cancer risk factors such as smoking and obesity. "But because we studied a very homogenous population, we think we might have overcome this limitation."
Michael Friedman, MD, president and chief executive officer of City of Hope in Duarte, Calif., a National Cancer Institute-designated comprehensive cancer center, tells WebMD that while Graaf's study is interesting he thinks it is too early to start prescribing statins to prevent cancer.
Friedman, who was not involved in the study, points out that this is not the first study to suggest such a benefit for statins, but "what is needed is a well-designed study that asks this specific question: Do statins reduce the risk of cancer?"
Moreover, Friedman says that "it is difficult enough to get people to take a statin to reduce cholesterol -- why would they take it to prevent cancer?"