Statins may reduce prostate cancer risk
Statins lower prostate-specific antigen (PSA) levels and appear to reduce the risk of prostate cancer itself, according to data from two trials presented at the American Urological Association meeting in Anaheim, Calif., in May.
A team of urologists at Duke University studied 1,214 men (mean age 60 years) prescribed a statin between 1990 and 2006 at the Durham (N.C.) VA Medical Center. The men had a median pre-statin PSA of 0.9 ng/mL and an LDL level of 144 mg/dL.
A year after starting a statin—usually simvastatin (Zocor) at 20 mg/day—the median decline in LDL levels was 27.5% and the median decline in PSA levels was 4.1%. For every 10% drop in LDL, PSA levels fell 1.6% when adjusted for age. When stratified by quartiles, men with the highest pre-statin PSA levels and the largest drop in LDL experienced a 15.2% average decline in PSA levels.
In the other study—done in Finland—a dose-dependent reduction in prostate cancer risk was found among users of statins. Investigators randomly selected 23,320 Finnish men listed in a national registry from among all those in their age group (55-67) and tracked their use of prescription drugs for six years. Each man was screened with a PSA assay at least once. A total of 6,755 men used statins and 934 used fibrates or resins.
Serum PSA was lower among users of any group of cholesterol drugs compared with nonusers. Statin users experienced a median decline in PSA values of 1.9%-3.0%. But most important, the incidence of prostate cancer was 2.8% among statin users compared with 4.7% among subjects who did not use statins. The researchers said the findings “suggest statins have a chemopreventive effect.”
Anthony Smith, MD, professor and chief of urology at the University of New Mexico in Albuquerque, said the Finnish study is important “because it is a very carefully controlled population of men, producing very good data.” He added that the findings suggest statins could be used in combination with finasteride and other 5a-reductase inhibitors to lower overall PSA values and the risk for advanced prostate cancer (earlier research has shown finasteride protective against the disease).
Several mechanisms of action could explain the PSA-lowering effect of statins. One is the link between cholesterol and levels of androgens such as testosterone. Cholesterol is a vital component of androgen synthesis.