スタチンによるがんのリスクはない(Abstract# 5035)

スタチン療法はどの部位またはどの患者群においてもがん発現の有害事象は有さない
Statin therapy has no adverse effect on cancer at any site or in any group of individuals
この種のスタディでは最も大規模なスタディの結果、スタチン療法はがん発現率や死亡を増加させる原因とはならないことが2010年European Society of Cardiology学会で報告された。コレステロール治療トライアル施行者による共同研究(Cholesterol Treatment Trialists' Collaboration)では、26の無作為化コントロールトライアルの対象170,000人のデータを解析した。これらの人々において10,000人余りががんを発症し、3,500人余りががんにより死亡した。解析の結果、がん発現率と死亡はスタチン内服群とプラセボ内服群とで全く同等であった。試験のサイズが大きかったために、スタチン療法が乳がんのようなある種のがんを引き起こす可能性があることやスタチン療法が一部の患者群においてがんの原因になる可能性があることなどの過去の仮説を否定することができた。この題目に関する過去の研究は、比較的小規模なスタディや他の因子の影響を除外できないスタディの結果に基づいていた。このスタディによりまた、高用量のスタチンは標準用量のスタチンと比べ、がんのリスクを上昇させないことも示された。既にコレステロールレベルの低い人々においても、より有効なスタチンによりコレステロールレベルを低下させてもがんのリスクは上昇しなかった。
Full Text

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 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 randomized 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. 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 randomized 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 coordinator 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".

The study was reported at the European Society of Cardiology Congress 2010. It 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.