Table 1.
Comparison of the two randomized controlled trials of 5-α reductase inhibitors for primary prevention of prostate cancera
| PCPT | REDUCE | |
|---|---|---|
| Agent studied | Finasteride 5 mg | Dutasteride 0.5 mg |
| Manufacturer | Merck & Co., Inc. | GlaxoSmithKline |
| Enzyme inhibition | 5-AR type 2 | 5-AR types 1 and 2 |
| Study size | 18,882 | 8,231 |
| Final analysis size, (drug:placebo) | 9,060 (4,368:4,692) | 6,729 (3,305:3,424) |
| Follow-up | 7 years | 4 years |
| Eligibility criteria | Age ≥55 years | Age 50 to 75 |
| Normal DRE | PSA 2.5 to 10 ng/mL | |
| PSA ≤3 ng/mL | Prior negative prostate biopsy (6-core minimum) within 6 months | |
| AUA Symptom Score <20 | AUA Symptom Score <25 (or <20 if taking α blockers) | |
| Excluded if | ||
| HGPIN | ||
| ASAP | ||
| > 1 biopsy prior | ||
| Gland volume > 80 cm3 | ||
| In-study measures | Annual PSA, DRE | Semiannual PSA, DRE |
| Finasteride PSA adjusted by 2× to 2.3× | Dutasteride PSA adjusted by 2× | |
| Triggers for biopsy | Triggers for biopsy | |
| Abnormal DRE | Not specified | |
| PSA > 4 ng/mL | Protocol biopsies at 2 and 4 years | |
| End-of-study biopsy offered to all without cancer after 7 years | ||
| Biopsies for cause, % | 39.4% | 12.0% |
| Primary end point | Prostate cancer detection | Prostate cancer detection |
| Finasteride 803 (18.4%) | Dutasteride 659 (19.9%) | |
| Placebo 1,147 (24.4%) | Placebo 858 (25.1%) | |
| RRR = 24.8%, 95% CI 18.6 to 30.6; P < 0.001 | RRR = 22.8%, 95% CI 15.2 to 29.8, P < 0.001 | |
| Secondary end points | Prostate volume at biopsy | Change in prostate volume from years 1 to 4 |
| Finasteride = 25.5 cm3 | Dutasteride 45.7 to 39.0 cm3 = -17.5% | |
| Placebo = 33.6 cm3 | Placebo 45.8 to 56.2 cm3 = +19.7% | |
| Relative difference = 24.1% | Relative difference in final volume = 30.1% | |
| HGPIN | ||
| Dutasteride 3.7% | ||
| Placebo 6.0% | ||
| RRR = 39.2%, 95% CI 24.2-51.1, p<0.001 | ||
| ASAP | ||
| Dutasteride 3.8% | ||
| Placebo 4.9% | ||
| RRR = 21.2%, 95% CI 1.3-37.1, p = 0.04 | ||
| High-grade disease | Gleason ≥7 detection | Gleason ≥7 detection |
| Finasteride 280 (6.4%) | Dutasteride 220 (6.7%) | |
| Placebo 237 (5.1%) | Placebo 233 (6.8%) | |
| RR = 1.67, 95% CI 1.44-1.93, p = 0.005 | RR = 1.02, p = 0.81 | |
| Gleason ≥8 detection | Gleason ≥8 detection | |
| Finasteride 90 (2.1%) | Dutasteride 29 (0.9%) | |
| Placebo 53 (1.1%) | Placebo 19 (0.6%) | |
| RR = 1.90; 95% CI and P value not given | RR = 1.5, 95% CI not given, P = 0.15 | |
| NNT to prevent 1 cancer | 17 | 20 |
a5-AR: 5-α reductase enzyme; 5-ARIs: 5-α reductase inhibitors; ASAP: atypical small acinar proliferation; AUA: American Urological Association; DRE: digital rectal examination; HGPIN: high-grade prostatic intraepithelial neoplasia; NNT: number needed to treat; RR: relative risk; RRR: relative risk reduction; 95% CI: 95% confidence interval.