THURSDAY, Feb. 5, 2009 (HealthDay News) -- Statins have clearly proven their mettle against heart disease, but the cholesterol-lowering drugs don't appear to possess cancer-fighting powers, a new animal study shows.
"We certainly didn't see any positive effects," said Ronald Lubet, program director in the division of cancer prevention at the National Cancer Institute. He led the study using mice and rats, which was published in the February issue of Cancer Prevention Research.
Lubet and his colleagues studied the effects of two popular cholesterol-lowering drugs, atorvastatin (Lipitor) and lovastatin (Mevacor), in warding off breast cancer. "The initial dose was about twice as high as what a person would typically use," he said. "The second dose was even higher."
Some researchers were hoping statins might have a double-edged effect, reducing heart disease risk as well as guarding against cancer. For instance, one recent study found that men who took statins had lower blood levels of prostate-specific antigen (PSA), a biomarker for prostate cancer risk.
And in a report published in the Journal of the National Cancer Institute in 2006, researchers found statins were associated with lower breast cancer incidence among women in the large-scale Women's Health Initiative trial and called for further study of the possible link.
Exactly how statins might fight cancer isn't certain. But Lubet's group did not see any such potential with the statins it tested.
The researchers gave Lipitor at a dose of either 125 milligrams or 500 milligrams per kilogram of body weight to the animals, mixing it into their diet, but it showed no anti-cancer effect.
They also compared the use of the anti-cancer drugs tamoxifen and bexarotene by themselves and with atorvastatin. The anti-cancer drugs reduced breast tumors in the animals, but adding the statin did not improve the effect.
The researchers also gave lovastatin at 100- and 500-milligram per kilogram of body weight to the animals but again did not uncover any cancer-fighting effects.
"In these two relatively standard animal models, [the statins] were not effective in preventing the development of tumors," Lubet said.
Lubet's group conducted the study, because the data to date has been mixed, with some studies showing the statins helped prevent cancer but others not. They wanted to see if clinical trials with humans, which are expensive, were warranted.
"To go to a large-scale trial, this [study] would not support it," Lubet said.
The new finding reflects the evidence to date from human studies, said Eric J. Jacobs, strategic director of pharmacoepidemiology at the American Cancer Society in Atlanta.
"The totality of the evidence from human studies also indicates that statins are unlikely to reduce the risk of breast cancer," Jacobs said. "While statins are proven effective in saving lives from heart disease, they should not be used in the hope of reducing the risk of cancer."
What would help?
"Maintaining a healthy weight will reduce a woman's risk of developing breast cancer, as well as many other serious health problems," he said.
To learn more about statins, visit the American Heart Association.