Prevention with Finasteride
description
Transcript of Prevention with Finasteride
Prevention with FinasteridePrevention with Finasteride
Ian M. Thompson, MD
October, 2009
F/U q3mo x 7yrAnnual DRE & PSA
Biopsy for cause
End of Study Biopsy
End of Study Biopsy
Enrollment
Placebo Finasteride
Randomization
The Prostate Cancer Prevention TrialThe Prostate Cancer Prevention Trial
PlaceboPlacebo
0 z 4.00 z 4.0
Finasteride PlaceboFinasteride Placebo Index IndexIndex Index
FinasterideFinasteride
X%X%
X%X%
PSA IndexPSA Index
PSAPSA(ng/ml)(ng/ml)
Total Number of Cancers Total Number of Cancers by Gleason Scoreby Gleason Score
803
20
457
19090
1147
55
776
18453
0100200300400500600700800900
100011001200
TotalCancers
2 - 4 5 - 6 7 8 - 10
Gleason Score
Num
ber o
f Can
cers
Finasteride = 4368Placebo - 4692
25% Risk Reduction Thompson et al, NEJM 349:215, 2003
Concerns Regarding PCPTConcerns Regarding PCPT
803
20
457
19090
1147
55
776
18453
0100200300400500600700800900
100011001200
TotalCancers
2 - 4 5 - 6 7 8 - 10
Gleason Score
Num
ber o
f Can
cers
Finasteride = 4368Placebo - 4692
It now appears that increased sensitivity of detection may have
led to increase in HG tumorsFinasteride:- Increases ability of PSA to detect
cancer and aggressive cancer.- Increases ability of DRE to detect
cancer- Improves ability of prostate biopsy to
detect cancer and to detect aggressive cancer.
AUC finasteride = 0.757AUC placebo = 0.681p<.001
PlaceboFinasteride
Thompson JNCI 2006;98:1128
AUC finasteride = 0.886AUC placebo = 0.824
Placebo
Finasteride
Thompson JNCI 2006;98:1128
Finasteride improves sensitivity of PSA
PSAPlacebo
PSAFinasteride Specificity Sensitivity
PlaceboSensitivityFinasteride
Cancer vs. No Cancer4.1 1.6 92.7% 24% 37.8% Gleason >7 versus other4.1 1.6 90.5% 39.2% 53%
Journal of the National Cancer Institute, 2006;98
Sensitivity Finasteride Placebo p-valueOutcome Prostate CA 21.3% 16.7% 0.013Gleason > 7 26.1% 21.7% 0.25Gleason > 8 38.3% 36.4% 0.86
No decrease in specificity with finasteride.
Journal of Urology 2007;177:1749-52.
Finasteride improves sensitivity of DRE
Impact of smaller prostate on sensitivity of biopsy for HG
disease
0
20
40
60
80
100
Finasteride Placebo
% H
G c
ance
rs fo
und
at b
iops
y
50%
70%
p = .01
Redman Modeling of Actual Cancer rates
CancerRR=0.70 (0.64, 0.76)p < .0001
Gleason ≤ 6RR=0.68 (0.57, 0.82)p < .0001
Gleason ≥ 7RR=0.72 (0.55, 0.94)p < .020%
5%
10%
15%
20%
25%
Placebo Finasteride
High gradeLow grade
8.2%
6.0%
8.7%12.9%
Conclusions
• Finasteride significantly reduces risk of cancer.
• High grade cancer detection may be increased through improved biomarkers and biopsy. (could be additional benefit)
• Relative risk reduction - > 25%
• Absolute risk reduction – depends on definition. As great as 7%, as low as 2%.