Statins and prostate cancer diagnosis and grade in a veterans population.

BACKGROUND: Although prostate cancer is commonly diagnosed, few risk factors for high-grade prostate cancer are known and few prevention strategies exist. Statins have been proposed as a possible treatment to prevent prostate cancer.
METHODS: Using electronic and administrative files from the Veterans Affairs New England Healthcare System, we identified 55,875 men taking either a statin or antihypertensive medication. We used age- and multivariable-adjusted Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer incidence among patients taking statins (n = 41,078) compared with patients taking antihypertensive medications (n = 14,797). We performed similar analyses for all lipid parameters including total cholesterol examining each lipid parameter as a continuous variable and by quartiles. All statistical tests were two-sided.
RESULTS: Compared with men taking an antihypertensive medication, statin users were 31% less likely (HR = 0.69, 95% CI = 0.52 to 0.90) to be diagnosed with prostate cancer. Furthermore, statin users were 14% less likely (HR = 0.86, 95% CI = 0.62 to 1.20) to be diagnosed with low-grade prostate cancer and 60% less likely (HR = 0.40, 95% CI = 0.24 to 0.65) to be diagnosed with high-grade prostate cancer compared with antihypertensive medication users. Increased levels of total cholesterol were also associated with both total (HR = 1.02, 95% CI = 1.00 to 1.05) and high-grade (HR = 1.06, 95% CI = 1.02 to 1.10) prostate cancer incidence but not with low-grade prostate cancer incidence (HR = 1.01, 95% CI = 0.98 to 1.04).
CONCLUSIONS: Statin use is associated with statistically significantly reduced risk for total and high-grade prostate cancer, and increased levels of serum cholesterol are associated with higher risk for total and high-grade prostate cancer. These findings indicate that clinical trials of statins for prostate cancer prevention are warranted.