In a 10-year study of more than 30,000 health professionals, long-term use of cholesterol-lowering drugs such as statins was associated with significantly reduced risk for advanced prostate cancer, according to a presentation at the annual meeting of the American Association for Cancer Research.

“We found that statin-takers cut their risk for advanced disease in half,” said Elizabeth Platz, ScD, MPH, investigator and presenter of the study.

Although earlier, smaller studies had linked use of statins to a lower risk of prostate and other cancers, such as breast and colon, the current study was the first to tie risk reduction to prostate cancer stage while tracking medication use before development of cancer.

Still, the researchers caution that data are not conclusive enough to warrant prescribing the drug to reduce cancer risk alone because many questions still linger, such as how they might contribute to delaying the cancer process more effectively than non-statins.

“Additional large studies may help confirm these results, but we also have some very important questions lingering as to which biochemical processes may link statins and reduced prostate cancer development,” says Platz. “Instead of preventing cancer, statins might work by stalling a tumor already in the prostate, helping to ensure that it doesn’t get worse.”

Platz noted that “when cholesterol-lowering drugs first came onto the market almost 20 years ago, there was even concern that they might increase the risk of cancer. Now, we are seeing more evidence that the opposite may be the case, but more research needs to be done.”

Researchers found no association between use of cholesterol-lowering drugs and whether or not men were diagnosed with early, curable forms of prostate cancer. But they did find that men who took cholesterol-lowering medications, as opposed to those not taking them, had half the risk of eventually developing advanced prostate cancers (283 men had cancer that invaded nearby tissue, had spread to other parts of the body, or was fatal) and one-third the risk of the most serious type of metastatic prostate cancer.

By the end of the study, more than 90 percent of men taking cholesterol-lowering drugs opted for statins, as opposed to other cholesterol-lowering drugs. “Since most of these study participants were taking statins during the time that we saw the highest levels of risk-reduction, we believe that statins more than any of the other cholesterol-lowering drug may have the biggest risk-reduction effects, but more studies are necessary to validate this,” said Platz.

Statins lower cholesterol by blocking an enzyme that controls its assembly. There are clues to suggest key cellular pathways involved in cancer-risk reduction may include statins’ effects on testosterone production, cell signaling, and inflammation. Or the drugs may play a role in changing prostate cancer cell membranes, which are rich in cholesterol.