Orlando, FL and Chicago, IL - New analyses of cancer rates among statin users in a population of veterans suggests that statins can reduce the risk of developing different types of cancer. A series of separate studies presented this past week at the American Society of Clinical Oncology (ASCO) 2005 Annual Meeting and Digestive Disease Week 2005 by researchers from the Louisiana State University (LSU) Health Science Center suggest that statins may slash by half the risk of at least six cancers.

The studies were based on data from the Overton Brooks VA Medical Center in Shreveport, LA, which houses a database containing health information on over 1.4 million veterans. Although the numbers of subjects varied in the six studies—and the breast-cancer study examined only female veterans—all used health data obtained between October 1998 and June 2004.

In an interview with heartwire, study author Dr Vikas Khurana (LSU) said that he and his colleagues had been looking at the role of statins in cancer prevention for several years, starting with a study in colon-cancer patients that indicated statins had no effect.

"When we looked at the data further, we realized we had not taken into consideration whether patients were taking statins before the development of cancer, and that was the reason for the lack of effect. Once we took patients who had been taking statins before the development of cancer, we saw a risk reduction across the board," he said.

Khurana says he and his coinvestigators have now seen benefits of statins in seven different cancers, including the new results presented at the ASCO meeting this past week. In each of the studies, the risk reduction seen in patients who had been on statins was roughly 50%, even after controlling for a range of factors appropriate to the different cancer types, such as age, weight, smoking, alcohol use, diabetes, gender, and race.

Khurana explains that the focus of statin research has, until recently, been on the lipid-lowering effects and less on the by-products of HMG-CoA reductase inhibition.

"We never pay any attention to what all the mid-level products are," he says. "It turns out that all those mid-level products are very important for cell-cycle regulation." Laboratory studies, he adds, have suggested that statins may interfere with the ability of cancer cells to replicate and increase apoptosis in cancer cells.

Khurana says it is much too soon to think of prescribing statins to patients at high risk for cancers, but he does think the evidence is strong enough to help decision-making for certain types of patients.

"At this stage, people might start requesting statins for cancer protection, but the drugs are obviously not indicated as such," he says. "However, if there is a patient who has high cholesterol and a family history of cancer or who is in some sort of high-risk cancer state—they have colon polyps, for example—you might want to preferentially put them on statins instead of other lipid-lowering agents."

He likens the evolving statin story to that of aspirin. "When we first started using aspirin, it was only for pain. And it turned out to be a cardioprotective agent, and it's now thought to protect against cancer also. I think we just need to watch these developments very closely. We've known that there were anticancer effects, but we cannot understand the magnitude of this effect 100% without randomized controlled trials."