Prostate cancer incidence among finasteride and alpha-blocker users in the Finnish Prostate Cancer Screening Trial.
BACKGROUND
The Prostate Cancer Prevention Trial has shown a protective effect of finasteride on prostate cancer in low-risk men. It is uncertain whether similar results can be expected when finasteride is used to treat benign prostatic hyperplasia.


METHODS
We performed an observational cohort study within the Finnish Prostate Cancer Screening Trial. Using a comprehensive prescription database on medication reimbursements during 1995-2004 of men using finasteride or alpha-blockers for benign prostatic hyperplasia, we evaluated prostate cancer incidence among 23 320 men screened during 1996-2004.


RESULTS
Compared to medication non-users, overall prostate cancer incidence was not significantly affected in finasteride users (hazard ratio 0.87; 95% CI 0.63-1.19). Incidence of Gleason 2-6 tumours, however, was decreased among finasteride users (HR 0.59; 95% CI 0.38-0.91), whereas incidence of Gleason 7-10 tumours was unchanged (HR 1.33; 95% CI 0.77-2.30). The protective effect concerned mainly screen-detected tumours. Overall prostate cancer risk was not significantly reduced among alpha-blocker users relative to non-users, but decreased incidence of high-grade tumours was observed (0.55; 95% CI 0.31-0.96).


CONCLUSIONS
The detection of low-grade, early-stage tumours is decreased among men who use finasteride for symptomatic BPH. The protective effect of finasteride can also be expected in men with benign prostatic hyperplasia.
Murtola
T J
TJ
School of Public Health, University of Tampere, FIN-33014 Tampere, Finland. teemu.murtola@uta.fi
Tammela
T L J
TL
Määttänen
L
L
Ala-Opas
M
M
Stenman
U H
UH
Auvinen
A
A
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D000368:Aged; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D018120:Finasteride / Q000627:therapeutic use*; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control*; D012307:Risk Factors; D013997:Time Factors
D000317:Adrenergic alpha-Antagonists; D018120:Finasteride; D017430:Prostate-Specific Antigen