NEW YORK (Reuters Health) - The cholesterol-lowering statin drugs are not linked to an increased risk of kidney cancer, suggests a new study. But there also isn't enough evidence to say that they offer any protection against the disease, researchers say.
One in four adults age 45 and older in the U.S. takes a statin to lower cholesterol and protect against heart disease. Some researchers were concerned when the drugs first hit the market that they might up cancer risks.
So far, the evidence on such a link "has been all over the place," said study author Dr. Toni Choueiri, from Harvard Medical School in Boston.
For kidney cancer in particular, "you had studies that showed increased risk (and) studies that showed no association," he told Reuters Health.
Choueiri and his colleagues used two large national data sets to hone in on the link between statin use and kidney cancer, which strikes more than 50,000 Americans each year.
The study involved close to 120,000 nurses and other health professionals who were followed for about 15 years. Every two years, the participants reported to researchers what medications they were taking, including statins, and any new diseases they had been diagnosed with.
Over the course of the study, 277 people were diagnosed with kidney cancer -- 66 of whom were taking statins at the time of the diagnosis.
When the researchers took into account factors such as smoking, weight, and diet, men who were taking statins had the same chance of being diagnosed with kidney cancer as men who weren't taking the drugs.
The researchers did find signs that women currently taking the drugs might have less cancer, but that finding could have been due to chance. Further studies will be needed to clear up that link, they wrote in the journal Cancer.
On the other hand, the authors didn't find that people who took statins for many years were protected against kidney cancer compared to those who only took them for a short time only.
Researchers have thought statins might affect cancer risk by altering the growth of tumors and the blood vessels that feed them.
But for now, "there's no convincing data that statins increase the risk of any cancer, but there's also no convincing data that statins decrease the risk," said Dr. Brian Strom, an epidemiologist at the University of Pennsylvania in Philadelphia.
There's no question that statins are beneficial for people with heart disease, and they're also very safe, said Strom, who wasn't involved in the new study. "People shouldn't either take (a statin) or stop taking it because of risk of cancer," he told Reuters Health.
Choueiri and his colleagues noted that they couldn't look at the link between individual drugs and kidney cancer risks, and it's possible that some statins may have an effect on cancer, while others don't.
SOURCE: bit.ly/qHI9gp Cancer, online July 12, 2011.