Helsinki, Finland - More than 16 years after the first patient was enrolled in the Scandinavian Simvastatin Survival Study (4S), the study drug has been shown unequivocally to improve survival over time, without producing an increase in cancer, when compared with placebo. By extending patient follow-up an additional five years, the 4S investigators, led by Dr Timo E Strandberg (University of Helsinki, Finland), have provided the longest follow-up data to date from a placebo-controlled statin study.
"The main finding of this 10-year follow-up study of the participants of 4S was that the survival benefit of patients allocated simvastatin compared with those allocated placebo that accrued during the double-blind trial period persisted during follow-up," the authors observe.
The 10-year results appear in the August 28, 2004 issue of the Lancet. The original 4S results appeared in the Lancet in 1994.Enduring benefits
The original 4S results saw simvastatin reducing lipid fractions and cholesterol concentrations as well as cardiovascular mortality over a five-year period, when compared with placebo. After an additional five years of follow-up, the investigators report that the 2221 patients who have remained on simvastatin—compared with patients who switched from placebo to statin at the five-year mark—have enjoyed a 17% reduction in CV mortality and a 24% reduction in coronary deaths.
4S: Relative risk reduction with simvastatin at five and 10 years
Relative risk: Trial conclusion (mean=5.4 y)
Relative risk: 10-y cumulative
Despite earlier risks that statins might increase cancer risk, the new data show long-term statin users to have a slightly reduced cancer risk, although this was not statistically significant.
"These findings are reassuring and in accordance with the negative findings on the risk of cancer in the Heart Protection Study," the authors note.
Indeed, they add, there have been biological and animal studies that have hinted at mechanisms through which statins might have anticancer effects, but only time will tell what further effects statins may have beyond the 10-year mark.
Heartwire from Medscape © 2004
Cite this: Ten-year follow-up from 4S study shows survival benefits of simvastatin endure - Medscape - Aug 27, 2004.