To the Editor: In the Prostate Cancer Prevention Trial, an increased rate of high-grade cancer was observed in the finasteride group (1). The recently published analysis by Redman et al. (2) suggests that this observation was the result of detection bias rather than a true increase. However, the marked increase in the estimated rate of high-grade cancer in the placebo group calls into question the validity of the model. If the true rate of high-grade cancer in the placebo group was indeed 8.2%, then ∼40% of all high-grade cancers were missed despite annual screening. Because untreated, high-grade prostate cancer is associated with a 45% rate of metastatic disease after 5 years (3), one may conservatively estimate that 100 cases of metastatic prostate cancer should have developed in the placebo group in the 5 years since publication of the Prostate Cancer Prevention Trial. Do the authors have follow-up data to confirm this expectation?

No potential conflicts of interest were disclosed.

1
Thompson
IM
,
Goodman
PJ
,
Tangen
CM
, et al
. 
The influence of finasteride on the development of prostate cancer
.
N Engl J Med
2003
;
349
:
215
24
.
2
Redman
MW
,
Tangen
CM
,
Goodman
PJ
,
Lucia
MS
,
Coltman
CA
 Jr.
,
Thompson
IM
. 
Finasteride does not increase the risk of high-grade prostate cancer: A bias-adjusted modeling approach
.
Cancer Prev Res
2008
;
1
:
174
81
.
3
Chodak
GW
,
Thisted
RA
,
Gerber
GS
, et al
. 
Results of conservative management of clinically localized prostate cancer
.
N Engl J Med
1994
;
330
:
242
8
.