5ARIs are recommended for men who have moderate-to-severe
lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE) secondary to
benign prostatic hyperplasia. Studies have confirmed the utility of combining 5ARIs with alpha-blockers; the MTOPS study showed that risk of overall
clinical progression was significantly reduced after 4.5 years with combination
therapy (
finasteride/
doxazosin) in comparison with either monotherapy, while the ongoing CombAT trial (
dutasteride/
tamsulosin) has for the first time shown benefit in improving symptoms for combination
therapy over monotherapies within 12 months of treatment. Data also suggest roles for 5ARIs in
prostate cancer. Several studies indicate that treatment with a 5ARI improves the performance of PSA testing for identifying men with
prostate cancer, while the PCPT showed a significant reduction in the risk of developing
prostate cancer with
finasteride. However, widespread use of
finasteride in this setting has been tempered by an apparent increase in high-grade disease observed in the study. The ongoing REDUCE study will provide further insight into
prostate cancer prevention with 5ARIs. 5ARI-containing regimens may have utility as less aggressive treatment options for patients who only have rising PSA after definitive local
therapy, and in patients with disease resistant to
androgen deprivation
therapy who have PSA progression. Current evidence therefore shows that 5ARIs are effective in treating LUTS/BPE and preventing
disease progression, and may also have a role in the prevention of
prostate cancer. The overlap between BPE and
prostate cancer may allow a more unified approach to managing these conditions, with 5ARIs having a central role.