The drugs that millions of Americans take to lower their cholesterol may also lower their risk of colon cancer, according to findings from an intriguing early study.

Researchers reported that people who took cholesterol-lowering statin drugs for five years cut their colon cancer risk in half, even when they had a family history of the disease or other risk factors.

The findings are published in the May 25 issue of The New England Journal of Medicine.

Although they are approved only for the prevention of heart disease, early trials suggest that statins such as Crestor, Lipitor, Zocor, and Pravachol may help protect against other types of cancer as well as prevent diseases like osteoporosis and Alzheimer's disease.

But experts say it is too soon to recommend these cholesterol-lowering drugs for the prevention of colon cancer or any of these diseases.

"There is just too much that we don't know," Ernest Hawk, MD, MPH, of the National Cancer Institute, tells WebMD. "We don't know who should take them [for cancer prevention], what dosage is needed, and how long people should stay on them. And we don't know anything about the safety of giving these drugs to people who don't have high cholesterol."

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'Window of Opportunity Closing'

Hawk says carefully designed clinical trials are needed to answer these questions, but time may be running out to do them. As statins are prescribed to more and more people to lower heart disease risk, the pool of potential study participants is quickly shrinking.

"The window of opportunity is closing," he says.

In an editorial accompanying the study, Hawk and NCI colleague Jaye L. Viner, MD, MPH, write that such trials could be invaluable for understanding seemingly unrelated diseases like heart disease, cancer, and Alzheimer's and how to prevent them.

"It is tempting to think that systemically targeting multiple diseases common to aging is not only theoretically feasible but within our reach," they write.

Gad Rennert, MD, PhD, who served as senior author for the colon cancer study, says cholesterol-lowering drugs may be as effective for reducing colon cancer risk as low-dose aspirin. He adds that combining the two low-cost drugs may prove even more protective.

Rennert tells WebMD that his own as yet unpublished research suggests that colon cancer risk can be reduced by 75 percent or even 80 percent by exercising regularly, eating lots of vegetables, and taking low-dose aspirin daily along with a statin.

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Half the Risk

In the newly reported study, Rennert and colleagues examined the use of cholesterol-lowering statin drugs among 1,953 people with colon or rectal cancer living in northern Israel and 2,015 people without the disease.

The study participants were asked to recall every medication they had used for at least five years, and prescription records were consulted to verify their responses.

The people without colon cancer were nearly twice as likely as cancer patients to report that they had taken statins for five years or more. The colon cancer risk reduction from statin use persisted even when other protective lifestyle factors, such as exercising regularly and eating vegetables, were taken into consideration.

Taking other cholesterol-lowering drugs was not shown to be associated with a reduced risk of cancer.

Statins are known to inhibit cell growth and have anti-inflammatory actions, and either or both of these mechanisms could help protect against cancer, Rennert says.

"Heart disease and cancer are the two big ailments of the western world," Rennert says. "It is incredible to think that we may be able to protect against both of them with the same extremely inexpensive drugs."

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By Salynn Boyles, reviewed by Brunilda Nazario, MD

SOURCES: Poynter, J. The New England Journal of Medicine, May 25, 2005; vol 352: pp. 2184-2192. Gad Rennert, MD, PhD, chairman, department of community medicine and epidemiology, Carmel Medical Center; director, CHS National Israeli Cancer Control Center. Ernest Hawk, MD, MPH, office of centers, National Cancer Institute, Bethesda, Md.