Cholesterol lowering statin drugs do not increase the cancer risks reported a study by the Tufts University School of Medicine.

An earlier study by the same authors had raised fears last year when they reported cancer rates rising in connection with lower cholesterol levels in patients who took the drugs called statins.  

Richard Karas, director of preventive cardiology at Tufts Medical Center and the senior author of the paper published in the Journal of the American College of Cardiology seemed to clear drugs, which include Pfizer Inc.'s Lipitor and AstraZeneca Plc's Crestor from causing cancer.

Another recent study that linked Vytorin, a cholesterol pill from Schering-Plough Corp. and Merck & Co., to cancer, also had reassuring results.

"When you put all of the information together, there is no evidence that statins increase the risk of cancer," Karas says in a news release. "This study should reassure those taking statins that they are not increasing their risk of cancer by trying to reduce their risk of cardiovascular disease." Karas further added, ``It's important that people don't worry that their medicines may be contributing to cancer. Our analysis says that they don't. It is your starting cholesterol level, not doing anything to alter it, that is associated with your risk of cancer,’ he said.

Findings from 15 statin trials involving nearly 100,000 patients, were analyzed in the study and as every person’s data was not previewed, the researchers say they were unable to pinpoint the reason cancer rates rose as cholesterol fell.

Karas said when studied together in the current study, known as a meta analysis, it becomes clear that on average they have no impact on the risk of cancer, he said, speaking of previous trials.

Karas and his colleagues were analyzing clinical trial data to evaluate other possible side effects and were asked to include cancer in their analysis. "Statin therapy, despite producing marked reductions in LDL cholesterol, is not associated with an increased risk of cancer," Karas and colleagues write.

Daniel Steinberg, from the University of California, San Diego said, ``If you measure serum cholesterol levels in a large, randomly chosen population and then simply follow that population for 5 years -- without intervention of any kind -- there will be more cancer deaths in those who had the lowest cholesterol levels to begin with,'' he said. ``Neither statin treatment itself not the low LDL levels induced by statins increases the risk of cancer.''

Lipitor is the world's top-selling drug with statins generating $ 33.7 billion from sales last year. These reduce cholesterol levels by blocking an enzyme the body needs to produce cholesterol and have been proven to reduce and prevent deaths caused by heart disease, which is the leading killer worldwide.