Popular statins widely used to lower cholesterol to prevent heart disease, apparently do not reduce the risk of cancer despite a flurry of recent studies suggesting a strong anti-cancer benefit, two scientific investigations report today.
Statins are the most commonly prescribed medications in the United States and as a result possess unrivaled name recognition: Lipitor, Zocor, Mevacor, Crestor, Pravachol and Lescol.
For years, evidence has mounted from a series of smaller studies that have suggested statins dramatically reduce the risk of many common forms of cancer, mostly through their powerful anti-inflammatory activity.
But when two separate teams of scientists further scrutinized whether statins could beat back the risk of cancer, they concluded that excitement over the drugs as cancer preventives may have peaked too soon.
“Statins do tons of things all over the body,” said C. Michael White, a professor of pharmacy at the University of Connecticut in Storrs, whose analysis on statins’ effect on cancer risk is reported in today’s Journal of the American Medical Association.
He added that statins have properties that may influence cancer development, just as they possess anti-inflammatory activity that may prevent the genesis of a tumor.
“When viewed together, these positive and negative effects cancel each other out,” White said. Among statins’ negative properties, White pointed to their tendency to decrease the body’s population of natural killer cells, immune system constituents capable of quashing early cancers.
He said his study along with another reported in today’s Journal of the National Cancer Institute have provided enough evidence to stop further pursuit of statins as cancer prevention agents.
“Both of these studies together answer a lot of questions,” he said.
White and his colleagues conducted what is known as a meta-analysis, a type of scientific study that gathers all pertinent data on a subject, then re-analyzes it to draw a new conclusion.
In this case, White and his team pooled data from 26 rigorously conducted clinical trials involving more than 86,000 patients who were divided among statin-takers and those who did not take the drugs. Statins noted in these studies included Lipitor and Zocor. Researchers originally concluded that statins played roles in the prevention of breast, prostate, lung and colorectal cancers.
But White and colleagues drew a different conclusion. “Perhaps because they were already being treated for heart disease, they might be taking better care of themselves.”
One study of Israeli patients last year found a 47 percent lower risk of colorectal cancer among statin-takers. Astounding results such as those led some researchers to half-jokingly remark that statins should be added to municipal water supplies.
Dr. Eric Jacobs, lead investigator of the study in the Journal of the National Cancer Institute, said that he and his team tried to re-create the Israeli results because of the potent implications statins then would have on cancer prevention.
“It was a little disappointing to us that we were not able to replicate this big reduction in risk,” said Jacobs, a senior epidemiologist with the American Cancer Society.