Data from two studies just published by a team of Norwegian researchers have suggested the possibility that men taking β-blockers for other (e.g., cardiovascular) conditions may have an increased survival benefit compared to other men who are diagnosed with and treated for high-risk or metastatic prostate cancer.
In the first of these two studies, Grytli et al. looked at data from the so-called Oslo II study conducted in in 2000. In this study. data from 6,515 patients were linked to data from the Cancer Registry of Norway and Statistics Norway. The authors used the combined database information to investigate prostate cancer risk and overall and prostate cancer-specific mortality and any association with the use of β-blockers.
Here is what they found:
- At baseline (when the Oslo II study was started)
- 776/6,515 men (11.9 percent) reported using a β-blocker.
- 212/6,515 men (3.3 percent) had been diagnosed with prostate cancer before the survey was carried out.
- So 6,303 eligible men could be followed for analysis of the incidence of prostate cancer.
- The average (median) follow-up was 122 months.
- During this follow-up period
- 448/6,303 men (7.1 percent) were newly diagnosed with prostate cancer.
- There was no association between β-blocker use and risk for a new diagnosis of prostate cancer risk (hazard ratio ([HR] = 1.05)
- When all eligible patients were considered (including those with a diagnosis of prostate cancer before the study was started)
- There was no statistically significant association between β-blocker use and prostate cancer-specific mortality (HR = 0.55; P = 0.16).
- There was no statistically significant association between β-blocker use and overall mortality (HR = 0.88; P = 0.57).
- In the subgroup of men who were scheduled to receive androgen deprivation therapy (ADT), as reported to the Cancer Registry (n = 263)
- β-blocker use was associated with a statistically significant reduction in prostate cancer-specific mortality (HR = 0.14; P = 0.032).
- β-blocker use did not appear to affect PSA level, Gleason score, or T-stage at diagnosis.
Based on these early data, the authors concluded that there was a possible benefit from β-blocker use in men with prostate cancer needing treatment with ADT.
In their second study, Grytli et al. looked at the data on all patients reported to the Cancer Registry of Norway as having a diagnosis of prostate cancer between 2004 and 2009 (n = 24,571). Of these patients, 3,561 were found to have high-risk or metastatic disease at the time of diagnosis.
Based on their analysis of data from this second cohort of patients, Grytli et al. showed the following:
- Median patient follow-up was 39 months.
- β-Blocker use was associated with a statistically significant reduced prostate cancer-specific mortality.
- The observed reduction in prostate cancer-specific mortality was independent of the use of drugs like statins or aspirin.
- There was no statistically significant association between β-blocker use and all-cause mortality.
Grytli et al. again concluded that β-blocker use was associated with a statistically significant reduction in prostate cancer-specific mortality in patients men with high-risk or metastatic prostate cancer at the time of diagnosis.
We already know that there is good evidence that the use of statins may be associated with an overall survival benefit for men with prostate cancer. Just the other day, we reported on data presented at the Genitourinary Cancers Symposium suggesting that men on long-term ADT might also receive some form of survival benefit from the use of anticoagulants.
It is becoming increasingly hard not to jump to the conclusion that, for men who need to start long-term ADT, it might be wise to also start taking some form of treatment that is known to lower risk for cardiovascular disease (unless one is already doing this). Of course it would be nice if we could also know which type of cardiovascular agent appeared to offer the greatest potential benefit under such circumstances!
As Grytli et al. are careful to point out, their “findings need validation from further observational studies.” Better still would be validation in randomized, prospective, double-blind, randomized clinical trials!