Last Updated: 2003-06-02 17:01:51 -0400 (Reuters Health)

CHICAGO (Reuters Health) - Cholesterol-lowering drugs called statins that are known to reduce the risk of heart attack and other complications of heart disease may also help prevent cancer, according to new research presented here on Sunday.

In a study comparing more than 3,000 cancer patients with more than 16,000 people who did not have cancer, the overall risk of cancer was 20 percent lower in people who took statins than in those who did not take the drugs. All of the participants were receiving at least one medication for cardiovascular disease.

Importantly, lead investigator Dr. Matthijs Graaf of the Academic Medical Center at the University of Amsterdam in the Netherlands said, only people who took statins for more than four years had a significant cancer risk reduction.

"People who used statins for less than four years did not have a significant risk reduction," Graaf said. The risk of cancer was 36 percent lower in people who took the cholesterol-lowering drugs for at least four years than in people who did not take the drugs.

The findings were presented at a press briefing during the 39th Annual Meeting of the American Society of Clinical Oncology.

Similarly, only statin users of more than 1,350 "defined daily doses" of statins had a significant risk reduction of 40 percent. A defined daily dose is an estimate of the amount of drug that is required for the daily treatment of an adult patient. Those that used less than this specific daily amount did not lower their cancer risk appreciably.

In the study, the researchers took into account several factors that could have affected the results, including diabetes, medical history and the use of several other types of medications. However, they were unable to take into account lifestyle factors, such as smoking.

Cancer risk returned to normal within six months of halting statin treatment.

The majority of statin users, about 80 percent, were taking simvastatin (Zocor) and since the effect of the different statins is not equal, "the results of this study may not be generalized to the use of other statins," Graaf said.

Graaf emphasized that more studies are needed and that, for now, it is not advisable that people start taking statins solely as a means of decreasing their risk of cancer.