This is a contribution from a member of THINCS,
The International Network of Cholesterol Skeptics

Letter to the editor of Lancet, sent 10. December 2002

Evidence that statin treatment causes cancer

Although the benefit of 22 fewer deaths from vascular disease was neutralised by 24 more deaths from cancer, the directors of the new statin trial PROSPER1 recommend pravastatin also for old people. They belittle the increased incidence of cancer by referring to their meta-analysis of all clinical statin trials according to which they found no overall increase in cancer. However, in that analysis non-melanoma skin cancer was excluded. Chemical carcinogenesis in human beings is a process that demands many years. If statin treatment promotes all types of cancer in human beings, as it seems to do in experimental animals,2 we should expect that the first ones to be seen were those that are easily detectable, the superficial ones, and we should also expect to see cancer primarily in old people, because the strongest risk factor for cancer is age. This is also what has happened. An increased incidence of non-melanoma skin cancer was observed in the simvastatin trials, 4S3 and HPS4 (no figures were given in the other trials). The difference between treatment and control group was not statistically significant in either of them, but it became significant if calculated together (simvastatin groups 256/12490, control groups 218/12490; p=0.028). In the CARE trial5 breast cancer, another readily detectable malignancy was seen in 12 women in the treatment group but in only one of the control individuals, a highly significant difference. The significant increase of cancer in people age 70-82 (PROSPER) is a further warning that cannot be dismissed by referring to trials where the mean age was much lower. 

Figure. Cancer incidence after cholesterol-lowering treatment of elderly individuals at risk of vascular disease. The incidence of skin cancer was not reported. The diagram is constructed using the data from the trial report. The difference between cancer incidences at year four was statistically significant (hazard ratio 1.25; CI 1.04-1.51). (This figure was not included in the letter to Lancet)

Uffe Ravnskov, MD, PhD, independent researcher,
Magle Stora Kyrkogata 9, S-22350 Lund, Sweden  

  1. Shepherd J, Blauw GJ, Murphy MB, et al. Pravastatin in elderly individuals at risk of vascular disease (PROSPER): a randomised controlled trial. Lancet 2002; 360: 1623-30.
  2. Newman TB, Hulley SB. Carcinogenicity of lipid-lowering drugs. JAMA 1996; 275: 55-60.
  3. Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S). Lancet 1994; 344:1383-9.
  4. Heart Protection Study Collaborative Group. MRC/BHF heart protection study of cholesterol lowering in 20 536 high-risk individuals: a randomised placebo-controlled trial. Lancet  2002; 360: 7-22.
  5. Sacks FM, Pfeffer MA, Moye LA, et al. for the Cholesterol and Recurrent Events Trial investigators. The effect of pravastatin on coronary events after myocardial infarction in patients with average cholesterol levels. N Engl J Med 1996; 335: 1001-9.

Editors answer:

20. December 2002

Dear Dr Ravnskov

Thank you for your communication on Evidence that statin treatment causes cancer, which you sent for publication in our Correspondence columns. I´m afraid we have decided not to accept your letter for publication on this occasion. Well over 3000 letters are submitted every year, and our criteria for acceptance are therefore very stringent. I wish you luck with acceptance in another forum.Yours sincerely

Zoë Mullan                                                                         
Senior Editor

Read also the published responses to PROSPER