Page 4 - Canadian Urological Association recommendations on prostate cancer screening and early diagnosis

Guideline: PSA screening and early diagnosis

however, a recently published case-control study nested study including men undergoing annual PSA screening iden-
within the Physicians Health Study cohort identified that tified that men with a PSA <1 ng/ml had a 10-year prostate
the risk of developing metastatic prostate cancer within 15 cancer detection rate of only 3.4%, of which 90% were con-
40
years among men in this age group was very low, even sidered low-risk. Furthermore, the nested case-control study
38
among men with PSA levels in the top decile. Thus, PSA referenced above identified that the risk of developing meta-
testing in these men may lead to biopsies and diagnoses static disease within 15 years for a man of any age with PSA
39
that are unlikely to provide benefit. The potential delay in <1 ng/ml is very low. As such, allowing a longer interval
diagnosis in the small proportion of men at this age with between PSA testing for these men is unlikely to result in an
clinically significant prostate cancer seems unlikely to lead increase in prostate cancer morbidity or mortality and will
to a missed opportunity for curative treatment. potentially reduce the risk of over-detection as a result of lead-
These recommendations are not directed towards men time bias or natural fluctuations in PSA levels.
with known germ-line mutations associated with prostate On the other hand, as baseline PSA levels rise above 1
cancer development (e.g., BRCA1, BRCA2, HOXB13). In ng/ml, the intermediate-term risk of developing both any
these cases, an individualized testing strategy after consulta- prostate cancer and clinically significant prostate cancer
tion with a clinical geneticist is most appropriate. increases substantially. 39-41 As such, we recommend that
3. For men electing to undergo PSA screening, we sug- these men, if electing PSA screening, should undergo test-
gest that the intervals between testing should be ing every two years. The ERSPC trial considered a positive
individualized based on previous PSA levels (Fig. 1). test to be a PSA level of 3 ng/ml, while the Goteborg trial
a. For men with PSA <1 ng/ml, repeat PSA test- considered a positive test to be between 2.5 and 3.4 ng/ml
ing every four years (Level of evidence: 3; (depending on the year of study). Thus, the optimal frequen-
Grade of recommendation: C). cy of PSA testing in men above these levels is unknown. For
b. For men with PSA 1–3 ng/ml, repeat PSA test- men with PSA >3 ng/ml, more frequent PSA testing intervals
ing every two years (Level of evidence: 3; can be considered. In addition, adjunctive testing strategies
Grade of recommendation: C). that estimate the risk of clinically significant disease may be
c. For men with PSA >3 ng/ml, consider more helpful for biopsy decision-making in these men (see below).
frequent PSA testing intervals or adjunctive 4. For men electing to undergo PSA screening, we sug-
testing strategies (Level of evidence: 4; Grade gest that the age at which to discontinue PSA screen-
of recommendation: C). ing should be based on current PSA level and life
Justification: Although the frequency at which PSA screen- expectancy.
ing should be performed has not been rigorously studied a. For men aged 60 with a PSA <1 ng/ml, con-
to date, we can extrapolate from the existing clinical trials sider discontinuing PSA screening (Level of
and observational studies to provide some guidance on this evidence: 2; Grade of recommendation: C).
issue. In particular, men in the screening arms of the ERSPC b. For all other men, discontinue PSA screening
trial and Goteborg trial underwent testing at intervals of at age 70 (Level of evidence: 2; Grade of rec-
four and two years, respectively, providing the basis for our ommendation: C).
recommendations. c. For men with a life expectancy less than 10
For men with a PSA level <1ng/ml, longer intervals between years, discontinue PSA screening (Level of evi-
PSA testing are appropriate. Indeed, a large prospective cohort dence: 4; Grade of recommendation: C).

Repeat testing
every 4 years a,b
PSA<1

Prostate cancer
screening shared PSA 1–3 Repeat testing
decision-making every 2 years a
(ages 50–70)

PSA>3
More frequent Consider adjunctive Biopsy shared
PSA testing c strategies d decision-making
PSA elevated Abnormal
Fig. 1. Prostate cancer screening pathway. Discontinue screening if life expectancy <10 years; consider discontinuation of screening if age >60 and PSA <1 ng/ml;
a
b
c more frequent testing interval can be considered; the optimal frequency is unknown; i.e., risk calculators, % free PSA, etc. PSA: prostate-specific antigen.
d
CUAJ • October 2017 • Volume 11, Issue 10 301