The use of beta-blockers in men with metastatic and high-risk prostate cancer was associated with a reduced risk of prostate cancer–specific mortality independent of statin or acetylsalicylic acid use, according to a study published in European Urology.
Given these results, beta-blocker use should be further investigated where large registries are available, wrote Dr. Helene Hartvedt Grytli of the Institute of Cancer Research at Oslo University Hospital and her coinvestigators. "This is the first study to assess the association between beta-blocker use and prostate cancer–specific survival in a large cohort of men with known disease aggressiveness at diagnosis," they wrote.
The researchers obtained data from the Cancer Registry of Norway for men diagnosed with prostate cancer between 2004 and 2009. They coupled these data, using participants’ national identification numbers, with information from the Norwegian Prescription Database on filled prescriptions for beta-blockers, statins, and acetylsalicylic acid (ASA). Patients were considered users of these agents if they had filled at least one prescription of the respective drug both before and after diagnosis.
Mortality data were obtained from the Cancer Registry of Norway. A total of 3,561 men were eligible for analysis after exclusion criteria were accounted for; the criteria included having low- or intermediate-risk disease and planned treatment with either radical prostatectomy or radiation therapy.
Beta-blocker use was independently associated with a reduced risk of prostate cancer–specific mortality in a multivariable model (adjusted subhazard ratio, 0.79; 95% confidence interval, 0.68-0.91; P = .001). The median follow-up time was 39 months (Eur. Urol. 2014;635-41).
Among beta-blocker users, 72% also used either ASA or statins. The investigators performed a survival analysis, adjusting for the use of these drugs to study any possible confounding effect. Statin use and ASA use were both associated with a reduction in prostate cancer–specific mortality when each drug was analyzed separately. Adjustment for the use of these drug classes did not substantially change the subhazard ratio for beta-blocker use.
The researchers did acknowledge a possible limitation of their study: "Unknown patient characteristics of this patient group might have confounded our results, and additional observation studies are warranted to establish whether beta-blocker use has an independent effect on prostate cancer progression and survival."
The study was funded by the South-Eastern Norway Regional Health Authority, Oslo University Hospital, and the University of Oslo.