Those who take statins may be putting themselves at a slightly increased risk of cancer, a new study released Monday finds.
However, this risk is far outweighed by the risks of not taking the often lifesaving cholesterol-lowering drugs, say researchers, including the study's authors.
Researchers of the study, which was published in the Journal of the American College of Cardiology, initially sought to find out whether statin drugs like Lipitor, Pravachol and Zocor harmed the liver.
Looking at recent studies, they found that statins only harmed the liver when taken in very large doses, but they also found an association between lower LDL ("bad") cholesterol and increased cancer risk.
Researchers were quick to state that they do not have any evidence that statins cause cancer, and would advise any patient on statins to continue taking them.
"At the current time, I don't think these findings should affect clinical practice," said Dr. Richard Karas of Tufts-New England Medical Center, one of the study's authors.
"We don't know what's the chicken and what's the egg, and we don't even know that the associations have anything to do with each other," he said.
Dr. Steven Nissen, past president of the American College of Cardiology, explained that the lowered cholesterol could easily be the result of cancer, rather than the cause.
"You don't know whether these people have low LDLs because they're taking statins, or they have low LDLs because they have cancer," he said, elaborating that the low cholesterol could be a symptom of a cancer that was not yet detected. "They're already sick."
Past research has even suggested that statin drugs may cut the risk of certain cancers, such as lung and prostate cancer.
Still, some said that the new study would lead them to exercise caution in prescribing statins.
Dr. Melvyn Rubenfire, the director of preventive cardiology at the University of Michigan, said that because of the long-term risk with statins, doctors may want to consider an alternative therapy if they deal with younger patients — 45 to 50 years old — or those with a family history of cancer when these patients are considered to be at low risk of heart problems.
"I avoid overly aggressive statin treatment for primary prevention in low-risk groups," Rubenfire explained.
But because researchers placed the increased cancer risk at 1 in a 1,000, many doctors concluded that even if the statins did cause cancer, that shouldn't dissuade patients from taking them.
Among them is Dr. John Messmer, the associate vice chairman for inpatient medicine at the University Physician Group in Palmyra, Pa.
"I get a similar argument from some patients who won't wear seat belts," he said. "They point out that they risk dying in a car fire or side impact if they wear their seat belt, even though the risk of that is lower than impacting the window or being thrown around the inside of the car in a crash.
"No reasonable scientist or physician believes that lowering cholesterol causes cancer, and there is no evidence to support such a claim," Messmer said. "On the other hand, there is clear evidence that lowering cholesterol reduces cardiovascular disease rates."