© The Canadian Journal of Urology™; 21(Supplement 2); June 2014
of the bladder, UTIs, significant BPH, significant bike
riding, or even sex in the 12 hours preceding a PSA
blood test.
The greatest risk factor for an enlarged, benign
prostate is age. It is important to realize that there are
age-specific levels of PSA. Using an age-specific PSA
threshold makes the PSA test to detect prostate cancer
more specific and sensitive. See Table 2.
10
Free/total PSA
If the free/total PSA ratio is greater than 0.2 (20%),
there is a less than a 10% chance of prostate cancer,
TABLE 2.
Age-related normal PSA levels
10
Age (years)
PSA threshold (ng/mL)
40-49
≤ 2.5
50-59
≤ 3.5
60-69
≤ 4.5
70 +
≤ 6.5
PSA = prostate-specific antigen
TABLE 1.
Prostate cancer screening studies
PLCO
ERSPC
Göteborg
Period
1993-2001
1994-2006
1995-2008
Number
76,693
162,243
20,000
Age
55-74 (13% > 70)
55-69
50-64
Site
Multiple centers (US)
7 countries (Europe)
1 city (Göteborg, Sweden)
Methods
PSA > 4 ng/mL
PSA > 3 ng/mL
PSA > 2.5 ng/mL (from 2005 on)
Abnormal DRE
Abnormal DRE
PSA > 2.9 ng.mL (from 1999-2004)
PSA > 3.4 ng/mL (from 1995-1998)
Follow up
Every 1 year X 6
Every 4 years
Every 2 years
11 years median follow up 9 years (complete)
78% had 14 year follow up
Contamination
52%
Not known
3%
Control Screened
Control
Screened Control
Screened
Prostate cancers
6% 7.3%
4.8% 8.2% 7.2% 11.4%
Prostate cancer deaths 44
50
326
214
78
44
Risk ratio
NS
20% (p = 0.04)
44% (p = 0.002)
NNS
-
1:1410
1:293
NNT
-
1:48
1:12
Adapted from Gomella et al.
Can J Urol
2011
7
PLCO = US Prostate, Lung, Colorectal, and Ovarian cancer screening trial
6
ERSPC = European Randomized study of Screening for Prostate Cancer
8
Göteborg = Göteborg randomised population based prostate cancer screening trial
9
NNS = number needed to screen
NNT = number needed to treat
and if it is < 0.10 (10 %), then there is a greater than
90% chance of prostate cancer. This test was originally
developed to help clarify the meaning total PSAvalues
between 4 ng/mLand 10 ng/mL, which fell in the gray
zone for prostate cancer.
Determining the free/total PSA ratio when total
PSA less than 1 ng/mL is of little value.
11
PSA velocity
Determining the PSAvelocity (rate of rise in PSAover
time) may improve the sensitivity of PSA tests. When
baseline PSA is between 4 ng/mL and 10 ng/mL, a
rise in PSA that is greater than 0.75 ng/mL/year may
indicate a higher risk of prostate cancer. Similarly, for
baseline PSA levels below 4 ng/mL, a rise in PSA of
0.4 ng/mL/year denotes a higher risk of prostate
cancer.
It was previously believed that an absolute
0.75 ng/mL/year rise in PSA indicated a suspicion of
prostate cancer. However, it is now generally accepted
that PSA velocity is age related. See Table 3. A small
rise in PSA, which reflects increased growth of benign
prostate tissue, can be normal in younger men.
3
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Barkin ET AL.
