In the largest and most reliable study of its type, the University of Oxford (UK) and the University of Sydney (Australia) have demonstrated that statin therapy is not a cause of increased cancer rates and deaths.

The conclusions of this study, presented at the European Society of Cardiology's Congress 2010 in Stockholm, will reassure the millions of people worldwide who are taking statins to lower cholesterol levels, and clarifies earlier research that had raised concerns of a causal link.

The Cholesterol Treatment Trialists' Collaboration examined data from 170,000 people captured from 26 randomised and controlled trials. Of these people, over 10,000 of them developed cancer and over 3,500 died from cancer. Analysis determined that cancer rates and deaths were exactly the same in people taking statin therapy as those being given a placebo tablet. The study was funded by the UK Medical Research Council, the British Heart Foundation and the National Health and Medical Research Council (Australia), and involved collaborators from all over the world.

Doctor Jonathan Emberson, University of Oxford British Heart Foundation Senior Statistician, notes, "Statin therapy had no adverse effect on cancer at any site or in any group of individuals, irrespective of their cholesterol levels. There was also no association of cancer with statin dose or duration."

Due to its large size, the study was able to refute previous suggestions that statin therapy might cause particular types of cancer, such as breast cancer, or that it might cause cancer in particular groups of people. Previous research into this topic had been based on relatively small trials or studies that could not exclude the effect of other factors. By contrast, this analysis of all the randomised trials provides the most reliable evidence about the benefits and risks of statin therapy.

The study also demonstrated that when comparing a high statin dose with a standard dose, cancer risk was not increased. Even among people with already low cholesterol levels, further reducing these levels with more potent statin regimens did not increase their risk of cancer. Commenting on this, Professor Colin Baigent of the Medical Research Council and co-ordinator of the Oxford team said, "This study demonstrates reliably that reducing LDL, or bad, cholesterol with statin therapy has no adverse effects on cancer, at least within a period of about 5 years."

Professor Rory Collins, British Heart Foundation Professor of Medicine and Epidemiology at the University of Oxford, and co-principal investigator of the project, concluded "These findings are extremely reassuring for patients. Statins are one of the most effective known therapies for the prevention of heart attacks and strokes, and this study should reassure the millions of people who are taking them worldwide."