Alth0ugh an overwhelming amount of evidence now points towards the beneficial effects of statins, most of the large statin studies have only had 5-year follow-up and there have been observational studies that have suggested a long-term increased risk of particular types of cancer, and of other non-vascular morbidity and mortality.

The 20,536 patients in the Heart Protection Study (HPS) were randomised to either simvastatin 40mg once daily or placebo and were followed up within the trial for 5.3 years. Following this period, patients were asked to discuss with their family doctor whether non-trial statin treatment should be prescribed. The patients were then followed up by mailing questionnaries biannually until a total of 11 years, with further details sought from family doctors or hospital records if required. The primary outcome during this period was major vascular-events, non-fatal myocardial infarction or coronary death, fatal or non-fatal stroke, and coronary or non-coronary revascularisation. Secondary outcomes were major vascular events, death from vascular and non-causes, and cancers at all sites.

The previously reported reduction in major vascular events associated with LDL cholesterol reduction was seen in this patient population during the 5 year follow-up period. After the trial ended, statin use and lipid concentrations were similar in the two groups, and in the subsequent 6 years there was no further significant reduction in major vascular events or vascular mortality. During the entire 11 year follow-up period there was no significant difference in total cancer incidence (RR: 0.98; 95% CI 0.92-1.05), nor further analysis looking at specific cancer sites, or non-vascular causes.

Conclusions:

This long-term follow-up of patients who have received prolonged statin therapy fails to recognise any hazards from doing so. These results suggest that extended statin therapy is safe with regards to the possible risk of cancer and non-vascular mortality, and has prolonged beneficial effects even after discontinuation of therapy.

• Heart Protection Study Collaborative Group, Bulbulia R, Bowman L, Wallendszus K, Parish S, Armitage J, Peto R, Collins R. Effects on 11-year mortality andmorbidity of lowering LDL cholesterol with simvastatin for about 5 years in20,536 high-risk individuals: a randomised controlled trial. Lancet. 2011 Dec 10;378(9808):2013-20