Prostate Cancer is the second leading cause of cancer-related deaths among men.
Indications of prostate cancer can be detected by testing for blood levels of prostate-
specific antigen (PSA) and by a digital rectal exam. Further testing may include
a biopsy. Although screening can help find many prostate cancers early, like
breast cancer screening, PSA screening is an area of contentious debate, and medical
science is still evaluating the evidence about whether the benefits of screening
and treatment outweigh the side effects and other risks.
Opponents of screening maintain that the risk of harm outweighs the modest benefits
and, therefore, that PSA screening should be uniformly discouraged. They
argue that the PSA does not detect cancer, only that a man may have it; that the
biopsies that detect cancer cannot reliably differentiate cancers that would never
cause a problem (about one-third to one-half of prostate cancers) from potentially
life-threatening cancers; that PSA testing has led to large numbers of men treated
for clinically insignificant disease; and in some important studies no decrease in all cause
death rates, just fewer deaths from prostate cancer. Opponents of testing also
point out that the side effects of treatment such as urinary and bowel incontinence
and impotence are serious and cause long-lasting detriments to quality of life.
Proponents of prostate cancer screening argue that screening is responsible for approximately
45% to 70% of the decline in age-adjusted prostate cancer mortality
observed in the U.S. over the past two decades and that PSA levels, family histories
and other risk factors such as race should guide screening decisions.
A 2014 evaluation of PSA test recommendations published in the JAMA suggested
that harms could be reduced and outcomes could be improved by considering PSA
testing every other year, and a high PSA threshold for biopsies. The review also
suggested that active surveillance or watchful waiting may be the optimal treatment
strategy for men with lower-risk prostate cancers, particularly with a lower PSA
level at diagnosis or a biopsy Gleason score of lower than 7, (the Gleason score is a
1-10 measure of how aggressive a prostate cancer is). Active surveillance includes
serial PSA tests, physical examinations, and biopsy with treatment administered at
a sign of more aggressive disease. Watchful waiting is observation with only palliative
treatment offered when disease progresses.
The 2017 recommendation statement from the U. S. Preventative Services Task
Force (USPSTF) notes that the largest trial to show a benefit of prostate cancer
screening found that slightly more than one man per 1000 offered screening avoided
death from prostate cancer, after an average follow-up of 13 years.206 207 There
is also evidence that three men per 1000 offered screening may avoid incurable
metastatic disease after an average follow-up of 12 years.
A 2017 review in the New England Journal of Medicine pointed out:209 “That there
is still no clarity about the usefulness and desirability of routine PSA-based screening
after 25 years and two large trials suggests that its net benefit is unlikely to be
more than marginal, whereas the harms are proven and substantial.”
Guidelines for screening have been promulgated by several professional groups.
The American Cancer Society recommends that starting at age 50, men should talk
to a health care provider about the pros and cons of testing so they can decide if
testing is the right choice for them. If you are Black or have a father or brother
who had prostate cancer before age 65, you should have this talk with a health care
provider starting at age 45.
In 2018 the U.S. Preventive Services Task Force (USPSTF) recommended that for
men aged 55 to 69 years, the decision to undergo periodic PSA-based screening for
prostate cancer should be an individual one and should include discussion of the potential
benefits and harms of screening with their clinician. The USPSTF recommends
against PSA-based screening for prostate cancer in men 70 years and older.
The American Urological Association (AUA)212 recommends shared decision making
for men aged 55 to 69 years. For men electing to be screened, an interval of
two years or more may be preferable to annual screening. The AUA recommends
against PSA screening in men younger than 40 years, against routine screening between
ages 40 and 54 years for men at average risk, and against routine screening in
men older than 70 years or any man with less than a 10-year to 15-year life expectancy.”
213 In 2018 the AUA released the following statement: “We agree with the
USPSTF that Black American men and men with a family history of prostate cancer
are at an increased risk of developing the disease, and that they should discuss with
their physicians the benefits and risks of testing in order to make a shared, informed
decision.”
A large trial evaluating the value of PSA screening was reported on in 2018. In
the cluster-randomized trial in the U.K., men aged 50 to 69 years had a single PSA
screening test or usual care, with an estimated 10-15% of men getting a PSA test.
Over a 10-year period, the one-time screening increased the detection of low-risk
prostate cancer cases but was not associated with a significant difference in cumulative
prostate cancer mortality.
Writing in the JAMA in 2018, H. Ballentine Carter recommends that first, physicians
should offer screening primarily to patients for whom the evidence of benefit
is strongest, i.e., those aged 55-69 years. And since older age is associated with
more aggressive prostate cancer, a very healthy older man with the prospects of
extended life might benefit from PSA testing. Nevertheless, routine screening of
average-risk men 70 years and older should be rare, because older men are more
likely than younger men to experience the harms of screening, diagnosis, and treatment.
Second, a 2- to 4-year PSA testing interval, rather than annual testing, could
reduce false-positive test results and overdiagnosis without substantially sacrificing
the benefits of screening. Third, a family history of cancer mortality related to
adenocarcinoma (including prostate cancer) and Black American race may identify
men with more to gain from screening compared with a man at average risk.
A 2020 article in the New England Journal of Medicine noted that increased PSA
screening contributed to a decline in the incidence of and deaths from metastatic
prostate cancer but did not reliably translate into increased longevity. And while
a few people receive substantial benefit from extensive PSA screening, many more
are exposed to over-diagnosis and over-treatment with needless biopsies and operations.
The authors suggest raising the PSA threshold for referral to urology and
likely biopsy from 4 to 10 ng/mL and careful evaluation by urologists of PSA level
trends and other factors, such as a Gleason scores, to guide decisions about treatment
or active surveillance.
A 2020 study in the New England Journal of Medicine considers that with the increased
emphasis on active surveillance and better detection, the balance of benefits
and harms of screening is more favorable for screening than is generally appreciated.
219 This is because PSA screening avoids incurable metastatic prostate cancer
disease and mortality and new methods of active surveillance diminish the harms
of overdiagnosis.
The field of prostate cancer screening is evolving rapidly with biopsies guided by
MRI, ultrasound, and the development of new genetic tests to help identify aggressive
cancers.
This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel.
