Men who use statins to lower their cholesterol are 30 percent less likely to see their prostate cancer come back after surgery compared to men who do not use the drugs, according to researchers at Duke University Medical Center. Researchers also found that higher doses of the drugs were associated with lower risk of recurrence.
The findings are published in the journal CANCER.
"The findings add another layer of evidence suggesting that statins may have an important role in slowing the growth and progression of prostate cancer," says Stephen Freedland, M.D., a member of the Duke Prostate Center and the Urology Section at the Durham Veterans Affairs Medical Center, and the senior author of the study. "Previous studies have shown that statins have anti-cancer properties, but it's not entirely clear when it's best to use them – or even how they work."
Researchers examined the records of 1319 men who underwent radical prostatectomy included in the Shared Equal Access Regional Cancer Hospital (SEARCH) database. They found that 18 percent of the men – 236 – were taking statins at the time of surgery.
Researchers followed the patients after surgery to evaluate recurrence rates, measured by slight rises in the PSA levels after surgery, a development known as "biochemcical recurrence." Time to biochemical recurrence is viewed as an important clinical factor because it is correlated with the risk of disease progression and death.
The authors found that 304 men had a rising PSA, including 37 (16 percent) of the statin users and 267 (25 percent) of the non-users. Taking into account various clinical and pathological features that differed between the two groups, the data showed that overall, statin use reduced the risk of biochemical recurrence by 30 percent.
Among men taking statins equivalent to 20 mg of simvastatin a day, the risk of recurrence was reduced 43 percent and among the men taking the equivalent of more than 20 mg of simvastatin a day, the risk of recurrence was reduced 50 percent. Men who took a statin dose the equivalent of less than 20 mg of simvastatin daily saw no benefit.
There were significant differences between those who took the drugs and those who did not. Statin users tended to be white, older and heavier than non-users. They also had lower clinical stages at diagnosis, but higher Gleason scores, a measure of tumor aggressiveness.
"These findings are intriguing, but we do need to approach them with some caution," says Robert Hamilton, M.D., a urologist at the University of Toronto and the lead author of the study. "For example, we don't know the diet, exercise or smoking habits of these men. So it's not entirely clear if the lower risk we detected is related to the statins alone – it could be due to other factors we were not able to measure. We do feel, however, that based on these findings and those from other studies, the time is ripe to perform a well-controlled randomized trial to test whether statins do indeed slow prostate cancer progression."