A meta-analysis reveals that use of 5-alpha reductase inhibitor drugs does not increase the risk of prostate cancer death
Prostate cancer (PC) is the second most common cancer in men and over 1.4 million new cases in 2020. A 2003 study suggested that 5-alpha reductase inhibitors (5-ARIs) such as finasteride, prevent or delay the appearance of prostate cancer. In addition, use of dutasteride, also gave rise to a lower risk of incident prostate cancer. However, the FDA warned in 2011 that 5-ARIs may increase the risk of a more serious form of prostate cancer. Despite this more recent data are conflicting. For example, in one study, use of 5-ARIs led to a delay in cancer diagnosis and worsened cancer-specific outcomes in men with PC. In contrast, another could not detect an association between 5-ARI use and prostate cancer death.
In the present study, researchers undertook a meta-analysis on the association of 5-ARI use and prostate cancer death. The primary outcome was the incidence of PC mortality among 5-alpha reductase inhibitor users and non-users.
5-alpha reductase inhibitor use and prostate cancer
There were 11 studies meeting the inclusion criteria, only one of which was an RCT and the remainder cohort studies. A total of 3,243,575 men were identified, 138,477 of whom were using a 5-ARI drug.
There was no significant association between 5-ARI use and prostate cancer death (hazard ratio, HR = 1.04, 95% CI 0.80 – 1.35, p = 0.79). In addition, there was also no association when restricting the analysis to exclude patients with a PC diagnosis at baseline (HR = 1.0, 95% CI 0.60 – 1.67, p = 0.99). When adjusting for prostate specific antigen level, there was a lower risk of prostate cancer mortality but this was non-significant (HR = 0.76, 95% CI 0.57 – 1.03, p = 0.08).