Editor—We agree with Ravnskov et al that little is known about the adverse effects of high dose statins but also propose that little is known about the long term safety of more modest doses used at present.1 Lifetime use of statins may equate to treatment for 30 years or more.2 As said by the authors, multicentre, large scale trials have established efficacy of these agents but are much less reliable in detecting uncommon serious adverse outcomes such as cancer.
Recent studies provide reassurance about the safety of statins with respect to all cause carcinogenicity in the short term3,4 and up to 10 years.5 However, although the length of postmarketing surveillance remains quite short compared with the medically accepted latency period for cancer of 20 years,2 it seems prudent to establish systems examining and linking large databases to allow extended follow-up for malignancy. Such monitoring can also help ascertain whether any class effect or dose response exists and whether certain categories of carcinogenicity are influenced by statins either favourably (as shown by some case-control studies) or deleteriously.
These data linkage systems should include a variety of stakeholders, among them regulatory authorities from different countries and the pharmaceutical industry, all cooperating in the provision of more robust information in this and other important areas of pharmacovigilance. Recent issues surrounding the long term uncertainty of cyclo-oxygenase-2 inhibitors and hormone replacement therapy have highlighted that drug safety must be proved rather than assumed, especially for drugs used very widely and long term.
Competing interests: SJH has received assistance via an Australian National Health and Medical Research Council public health postgraduate research scholarship, scholarship application ID No 237059. AT has received funding for studies and speakers' fees from pharmaceutical industry companies including AstraZeneca, Bristol-Myers Squibb, Merck Sharp and Dohme, Pfizer, and Sankyo. MN has received funding for studies and consultancies from pharmaceutical industry companies including AstraZeneca, Bayer, Sanofi-Aventis, Sanofi-Synthelabo, Bristol-Myers Squibb, Merck Sharp and Dohme, and Pfizer. JJMcN has served on advisory boards for Pfizer, GlaxoSmithKline, Johnson & Johnson, Bristol-Myers Squibb, Schering-Plough, Sanofi-Aventis, and Merck Sharp and Dohme.
References
- 1.Ravnskov U, Rosch PJ, Sutter MC, Houston MC. Should we lower cholesterol as much as possible? BMJ 2006;332: 1330-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Newman TB, Hulley SB. Carcinogenicity of lipid-lowering drugs. JAMA 1996;275: 55-60. [PubMed] [Google Scholar]
- 3.Baigent C, Keech A, Kearney PM, Blackwell L, Buck G, Pollicino C, et al. Efficacy and safety of cholesterol-lowering treatment: prospective meta-analysis of data from 90,056 participants in 14 randomised trials of statins. Lancet 2005;366: 1267-78. [DOI] [PubMed] [Google Scholar]
- 4.Kaye JA, Jick H. Statin use and cancer risk in the general practice research database. Br J Cancer 2004;90: 635-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Strandberg TE, Pyorala K, Cook TJ, Wilhelmsen L, Faergeman O, Thorgeirsson G, et al. Mortality and incidence of cancer during 10-year follow-up of the Scandinavian simvastatin survival study (4S). Lancet 2004;364: 771-7. [DOI] [PubMed] [Google Scholar]