(BlackDoctor.org) — Screening refers to testing to find a disease such as
cancer in people who do not have symptoms of that disease. For some types of
cancer, screening can help find cancers in an early stage when they are more
easily cured. Prostate cancer can often be found early by testing the amount of
prostate-specific antigen (PSA) in the blood. Another way to find prostate
cancer is the digital rectal exam (DRE), in which your doctor inserts a gloved
finger into the rectum to feel the prostate gland. If the results of either one
of these tests are abnormal, further testing is needed to see if there is a
cancer. If you have routine yearly exams and either one of these test results
becomes abnormal, then any cancer you might have has likely been found at an
early, more treatable stage. The DRE and the PSA test are both discussed in more
detail later in this document.
Since the use of early detection tests for prostate cancer became fairly
common (about 1990), the prostate cancer death rate has dropped. But it isn’t
yet clear if this drop is a direct result of screening or caused by something
else, like improvements in treatment.
Unfortunately, there are limits to the current screening methods. Neither the
PSA test nor the DRE is 100% accurate. Abnormal results of these tests don’t
always mean that cancer is present, and normal results don’t always mean that
there is no cancer. Uncertain or false test results could cause confusion and
anxiety. Some men might have a prostate biopsy (which carries its own small
risks, along with discomfort) when cancer is not present, while others might get
a false sense of security from normal test results when cancer is actually
present.
There is no question that the PSA test can help spot many prostate cancers
early, but another important issue is that it can’t tell how dangerous the
cancer is. Finding and treating all prostate cancers early may seem like a
no-brainer. But some prostate cancers grow so slowly that they would likely
never cause problems. Because of an elevated PSA level, some men may be
diagnosed with a prostate cancer that they would have never even known about at
all. It would never have caused any symptoms or lead to their death. But they
may still be treated with either surgery or radiation, either because the doctor
can’t be sure how aggressive the cancer might be, or because the men are
uncomfortable not having any treatment. These treatments can have side effects
that seriously affect a man’s quality of life. Doctors and patients are still
struggling to decide who should receive treatment and who might be able to be
followed without being treated right away (an approach called “watchful waiting”
or “expectant management”).
Studies are under way to try to determine if early detection tests for
prostate cancer in large groups of men will lower the prostate cancer death
rate. Early results from two large studies haven’t offered clear answers.
Interim results from a study done in the United States found that annual
screening with PSA and DRE detected more prostate cancers, but it did not lower
the death rate from prostate cancer. A European study did find a lower risk of
death from prostate cancer with PSA screening (done about once every 4 years),
but the researchers estimated that about 1,400 men would need to be screened
(and 48 treated) in order to prevent one death from prostate cancer. Neither of
these studies has shown that PSA screening helps men live longer (lowered the
overall death rate).
Prostate cancer tends to be a slow growing cancer, so the effects of
screening in these studies will likely become clearer in the coming years. Both
of these studies are being continued to see if longer follow-up will provide
more definitive results.
The American Cancer Society (ACS) feels that available evidence does not
support routine screening for all men. The ACS recommendation (see below) is
that men should make informed decisions based on available information,
discussion with their doctor, and their personal perspectives on the benefits
and side effects of screening and treatment.
Until more information is available, whether you have the tests is something
for you and your doctor to decide. There are many factors to take into account,
including your age and health. If you are young and develop prostate cancer, it
will probably shorten your life if it is not caught early. If you are older or
in poor health, then prostate cancer may never become a major problem because it
is generally a slow-growing cancer.
ACS recommendations for the early detection of
prostate cancer
The American Cancer Society does not support routine testing for prostate
cancer at this time. The ACS does believe that health care professionals should
discuss the potential benefits and limitations of prostate cancer early
detection testing with men before any testing begins. This discussion should
include an offer for testing with the prostate-specific antigen (PSA) blood test
and digital rectal exam (DRE) yearly, beginning at age 50, to men who are at
average risk of prostate cancer and have at least a 10-year life expectancy.
Following this discussion, those men who favor testing should be tested. Men
should actively take part in this decision by learning about prostate cancer and
the pros and cons of early detection and treatment of prostate cancer.
This discussion should take place starting at age 45 for men at high risk of
developing prostate cancer. This includes African American men and men who have
a first-degree relative (father, brother, or son) diagnosed with prostate cancer
at an early age (younger than age 65).
This discussion should take place at age 40 for men at even higher risk
(those with several first-degree relatives who had prostate cancer at an early
age).
If, after this discussion, a man asks his health care professional to make
the decision for him, he should be tested (unless there is a specific reason not
to test).
Recommendations of other organizations
No major scientific or medical organizations, including the American Cancer
Society (ACS), American Urological Association (AUA), US Preventive Services
Task Force (USPSTF), American College of Physicians (ACP), National Cancer
Institute (NCI), American Academy of Family Physicians (AAFP), and American
College of Preventive Medicine (ACPM) support routine testing for prostate
cancer at this time.
These organizations (the ACS, AUA, ACP, NCI, AAFP, ACPM, and the USPSTF)
recommend that health care professionals discuss the possible benefits, side
effects, and questions about early prostate cancer detection and treatment so
that men can make informed decisions taking into account their own situation and
risk.
The USPSTF published an update of its recommendations in 2008. It concluded
that the risks of screening for prostate cancer outweigh the benefits for men
age 75 years or older (as well as for men whose life expectancy is 10 years or
fewer). For these men, the USPSTF is now recommending against prostate cancer
screening. For men younger than 75 years old who have a life expectancy more
than 10 years, the USPSTF indicated that the studies completed so far still do
not provide enough evidence to know whether the benefits of testing for early
prostate cancer outweigh the possible risks. For men in this age group, the
USPSTF continues to recommend that health care providers discuss the potential
benefits and known harms of PSA screening and then allow the patients’ personal
preferences to guide the decision of whether to order the test.
In addition, the American Cancer Society and the American Urological
Association recommend that health care professionals