A cohort-based study of 1,001 men with prostate cancer shows that those men who took cholesterol-lowering statins had a lower risk of dying from their prostate cancer vs men who did not take these medications. The study also found that recurrence and progression were not related to statin use. The study is published in the Prostate.
“I think this study goes along with the growing body of evidence of observational studies—which have their strengths and weaknesses—that statins may have a role for delaying prostate cancer progression,” said Stephen Freedland, MD, a prostate cancer oncologist at the Duke University Medical Center in Durham, North Carolina, who was not involved in the research.
The men in the population-based study, all based in the Seattle area, were followed for an average of 7.5 years. The long-term analysis found those men who used statins throughout their prostate cancer diagnosis and treatment to control their cholesterol had a 1% risk of death compared with a 5% risk of death for non-statin users at 10 years (P < .01). This five-fold increase in risk of death was after controlling for major patient characteristics, including age, stage of prostate cancer, body mass index, type of treatment, history of comorbidities (such as diabetes), and smoking. There were a total of 123 deaths during the follow-up period, including 39 deaths from prostate cancer.
Previously, cohort-based studies have analyzed the link between statin use and prostate-specific antigen (PSA) levels, but this is the first study to link statin use and prostate cancer–specific mortality, said Janet L. Stanford, PhD, lead author of the study, epidemiologist, and co-director of the Prostate Cancer Research Program at the Fred Hutchinson Cancer Research Center in Seattle. A recent meta-analysis did not find a link between PSA recurrence and statin use.
Of the participants, 29% (289 participants) were statin users prior to their prostate cancer diagnosis, and 71% were non-statin users. The majority of patients in both groups (72%) had localized prostate cancer, and 14% had regional prostate cancer. Key differences between the statin user and non-user groups were age and comorbidities: Statin users were slightly older (mean age of 63.1 years compared with 60.9 years for non-statin users), more likely to have diabetes, and more likely to use aspirin or other nonsteroidal anti-inflammatory drugs. Statins used by patients were atorvastatin, simvastatin, lovastatin, and pravastatin.
Previous studies have suggested that statins may have an anti-cancer function. Whether the anti-activity of statins is related to their role in cholesterol-targeting or if it is through a different mechanism remains to be seen.
The study does not yet suggest that clinicians should recommend statins for either prostate cancer prevention or treatment. Previous cohort-based studies have had varying results—supporting the benefit of statins for prostate cancer, or showing no link, as well as a study that showed an increased risk of prostate cancer. The jury is still out on whether statins can benefit a patient’s prostate cancer prognosis.
Currently, a small clinical trial of approximately 44 patients is ongoing to see whether simvastatin had effects on non-cholesterol mechanisms in men who are undergoing a prostatectomy for their prostate cancer. However, a large randomized clinical trial is needed to understand whether statins indeed lower the risk of mortality due to prostate cancer. “This is certainly not the first study to show a positive effect of statins on prostate cancer, but it certainly adds to the body of literature that supports the notion that we need to be doing clinical trials to test this hypothesis,” said Freedland.