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.

Hamilton and Freedland BMC Medicine 2011 9:105   doi:10.1186/1741-7015-9-105

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