Researchers have found that the effective cholesterol-reducing drug, statin, is not equally potent in preventing breast cancer.
Prior studies have shown some but limited efficacy in breast cancer models when these drugs were given through a method that would be the equivalent of intravenously in humans.
However, that is not the way people take statins.
During the study, scientists conducted laboratory work in animals to determine if drugs like atorvastatin and lovastatin actually prevent both ER-positive and ER-negative breast cancer.
"We saw no real efficacy from either statin," said Ronald Lubet, Ph.D., an NCI program director.
Atorvastatin was administered at either 125 or 500 mg/kg in the diet of rats, and it did not alter the incidence of estrogen receptor-positive mammary cancers or its multiplicity. Similarly, no effect of atorvastatin was observed in an estrogen receptor-negative model in mice.
Lovastatin was given at 100 and 500 mg/kg, and it showed no significant preventive -effect similar to atorvastatin.
Lubet said the research into statin use and cancer prevention would continue.
"There is always the question of whether there will be a subset of breast cancer where this class of agents will be effective, but the answer at this point is that the present preclinical studies do not support the use of statins as general breast cancer preventive agents" he added.
The study appears in Cancer Prevention Research, a journal of the American Association for Cancer Research.