Related Experiment Video
Updated: Jun 25, 2025
A Bioluminescent and Fluorescent Orthotopic Syngeneic Murine Model of Androgen-dependent and Castration-resistant Prostate Cancer
Published on: March 6, 2018
Five-alpha reductase inhibitors and risk of prostate cancer among men with benign prostatic hyperplasia: A historical
Dixa B Thakrar1, Ian J Douglas1, Liam Smeeth1
1London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.
Abstract:
Background: Five-alpha reductase inhibitors (5ARIs) are used in the management of benign prostatic hyperplasia (BPH). 5ARIs prevent the conversion of testosterone to dihydrotestosterone, which is important in prostate development. It has been suggested that 5ARIs can be used a chemopreventative agent for prostate cancer. The aim of this study was to assess the risk of prostate cancer associated with 5ARI use among men with BPH. Methods: Using Clinical Practice Research Datalink (CPRD) from 1992 to 2011 in UK, prostate cancer risk was retrospectively compared in men with a new diagnosis of BPH, with no history of prostate cancer who were treated with 5ARIs, to men treated with alpha blockers (ABs) and those given no pharmacological treatment. Incidence rate of prostate cancer was calculated by treatment group; the association between BPH treatment group and prostate cancer was estimated by a multivariate Cox model. Results: 77,494 men with newly diagnosed BPH were included. The crude incidence rate of prostate cancer was 892.4 cases per 100,000 person-years amongst those treated with 5ARIs, compared with 1209.0 and 1542.9 in those treated with ABs and untreated individuals, respectively. The HR adjusted for potential confounders was 0.79 (0.72-0.86) for 5ARI vs ABs and 0.72 (0.66-0.79) for 5ARI vs untreated. After excluding the first year after BPH diagnosis, adjusted HRs attenuated to 0.87 (0.79-0.97) for 5ARI vs ABs and 0.97 (0.87-1.08) for 5ARI vs untreated. Conclusion: Among men diagnosed with BPH, we found evidence of lower risks of subsequent prostate cancer in those treated with 5ARIs, but this appeared to be driven by cases diagnosed within a year of BPH, possibly reflecting prevalent prostate cancers that were initially misdiagnosed. After excluding the first year after BPH diagnosis, there was little evidence of a reduced prostate cancer risk in those taking 5ARIs.
Insights
Five-alpha reductase inhibitors (5ARIs) show a lower risk of prostate cancer in men with benign prostatic hyperplasia (BPH). However, this benefit may be due to early misdiagnosis, with little evidence of reduced risk after the first year.
Area of Science:
- Urology
- Oncology
- Pharmacology
Background:
- Benign prostatic hyperplasia (BPH) is commonly managed with five-alpha reductase inhibitors (5ARIs).
- 5ARIs inhibit testosterone to dihydrotestosterone conversion, a key factor in prostate development.
- The potential chemopreventative role of 5ARIs in prostate cancer is under investigation.
Purpose of the Study:
- To evaluate the association between 5ARI use and prostate cancer risk in men diagnosed with BPH.
- To compare prostate cancer incidence rates among men treated with 5ARIs, alpha blockers (ABs), or no pharmacological treatment.
Main Methods:
- Retrospective cohort study using UK Clinical Practice Research Datalink (1992-2011).
- Included 77,494 men with newly diagnosed BPH and no prior prostate cancer history.
- Prostate cancer risk assessed using multivariate Cox models, comparing 5ARI users to AB users and untreated individuals.
Main Results:
- Crude incidence rates: 892.4/100,000 person-years (5ARIs), 1209.0 (ABs), 1542.9 (untreated).
- Adjusted Hazard Ratios (HRs): 0.79 (5ARI vs. ABs), 0.72 (5ARI vs. untreated).
- After excluding the first year post-diagnosis, adjusted HRs attenuated to 0.87 (5ARI vs. ABs) and 0.97 (5ARI vs. untreated), suggesting limited benefit.
Conclusions:
- Initial findings suggest lower prostate cancer risk with 5ARIs in BPH patients.
- This apparent benefit may be influenced by prevalent prostate cancers diagnosed within the first year, potentially due to misdiagnosis.
- Excluding early-diagnosed cases reveals minimal evidence of reduced prostate cancer risk associated with 5ARI use in BPH management.
Related Concept Videos
01:20Disorders of the Male Reproductive System
Prostate disorders are another major concern. These conditions can impair urinary flow due to the prostate's location around the urethra....
01:22Adrenergic Antagonists: Pharmacological Actions of ɑ-Receptor Blockers
α1-blockers: These drugs inhibit α1-adrenoceptors on smooth muscle cells, resulting in vasodilation. This vasodilation lowers blood pressure, making α1-blockers valuable in treating hypertension. Additionally,...
01:28Treatment for Pulmonary Arterial Hypertension: Phosphodiesterase Inhibitors
Among the PDE5 inhibitors, sildenafil (Revatio) stands out as a competitive and selective inhibitor. It operates by elevating cellular levels of cGMP and augmenting signaling through the cGMP-PKG pathway, promoting vasodilation. Upon oral...
01:17Adrenergic Antagonists: Chemistry and Classification of ɑ-Receptor Blockers
Nonselective α-blockers: Nonselective α-blockers contain haloalkylamine or imidazoline...
01:25Antihypertensive Drugs: Direct Renin Inhibitors
01:23Treatment for Pulmonary Arterial Hypertension: Prostacyclin Receptor Agonists
These agonists bind to the IPR receptor situated on the plasma membrane of the pulmonary artery smooth muscle cells. This binding triggers a cascade of reactions known as the GS-AC-cAMP-PKA pathway. This pathway results in the relaxation of smooth muscle...