Early Detection and Medical Checkups
Although having annual medical checkups and recommended tests will
not prevent prostate cancer, both are crucial to detecting prostate cancer
in its earliest stages. Detecting prostate cancer early, which means detecting
it before men experience symptoms and before the cancer leaves the prostate
gland, is the key to surviving this disease.
CPCN advises all men over the age of 45 to insist that their doctor
check for signs of prostate cancer during annual checkups. Also, if
you are at a high risk for developing prostate cancer—for instance,
if you are of African descent or if your family has a history of prostate
cancer—you should start being tested annually at age 40. (For the CPCN position on early detection, click here)
Currently, there are two main ways for the doctor to check for signs
of prostate cancer. The first is the digital rectal exam (DRE), and
the second is a blood test called the PSA (prostate-specific antigen)
test.
DIGITAL RECTAL EXAM
This exam has been in use for many years, and it has often been the
stuff of comedy skits. In spite of the fact that some men (and even
some doctors) find the test a bit disagreeable, the digital rectal exam
is a useful tool in the detection of prostate cancer. Why? Even though
there is a blood test (the PSA test) that can help doctors detect prostate
cancer, some men have prostate cancer that does not greatly affect the
level of prostate-specific antigen in their blood. For these men, the
digital rectal exam is the best bet for detecting prostate cancer early.
During a DRE, the doctor inserts a gloved and lubricated finger into
the rectum and feels the back part of the prostate for abnormalities.
The doctor is checking the size and shape of the prostate and whether
there are any hard, lumpy, or tender areas. Prostate cancer feels firm
or hard, and, sometimes, it causes the prostate to become asymmetrical
or irregularly shaped. As you can see from the illustration, only a
portion of the prostate can be felt during the exam. Fortunately, this
rear area of the prostate is where most prostate cancers develop.
Although useful, the DRE is a very subjective test, and the accurate
diagnosis of a potential problem relies heavily on the skill and experience
of the doctor doing the examination. Urologists are usually expert at
performing the DRE and interpreting findings, but many family doctors,
too, have considerable experience. If your doctor does not perform regular
DREs, or does so reluctantly and hastily, get a different doctor.
THE PROSTATE-SPECIFIC ANTIGEN (PSA) TEST
PSA, or prostate-specific antigen, is an enzyme produced mainly
by the cells lining the ducts of the prostate. Its job is to help the
semen remain in liquid form after ejaculation. Normally, then, PSA is
found in significant amounts only in semen or in the prostate gland
itself. In the 1980s, however, scientists found a way to detect miniscule
quantities of PSA in the blood stream, and, soon after, they observed
that, if men had more than a barely detectable amount of PSA in the
blood, they were more likely to have prostate problems: an enlarged
prostate, for example, or even prostate cancer.
Currently, PSA is measured in nanograms per millilitre. (To give you
a reference point, one nanogram is one billionth of a gram (1/1,000,000,000),
and it is the average weight of a human cell.) Typically, between 0
and 4 nanograms per millilitre of PSA is considered in the normal range.
However, doctors are constantly finding ways to use PSA readings with
more accuracy to determine whether a particular man might have early-stage
prostate cancer, and they now adjust for factors such as a man’s
age; his race, family history of cancer, or other risk factors; and
whether there has been an increase in his PSA level since his last test.
Please note: If you do have a higher than normal amount of PSA in your
blood, it does not mean that you have prostate cancer. Aging and other
conditions, such as benign prostatic hyperplasia (BPH) or prostatitis,
can cause abnormally high PSA levels.
For more information on the use of the PSA test in the detection, monitoring,
and treatment of prostate cancer, click here.
PSA tests, statin use, and prostate cancer: Persistent questions, CPCN
PSA Velocity and PSA Testing: Recent Happenings, CPCN
Early prostate cancer screening may reduce mortality rate by
35%, CPCN
Grant Wing, Preventative Medicine—PSA tests best means
of early detection, CPCN
Dr. Michael Wosnick, Earlier detection, better treatments, improving
prognoses,Globe and Mail Supplement, Wednesday, September 21,
2005, p. 3
Our position on early detection, CPCN
Prostate Cancer Screening: A Survey of Primary Care Providers in Newfoundland
and Labrador, CPCN
What is a false positive? CPCN
You’re never too old to do something smart,
Red Green campaign promoting early detection, CPCN,
View the Red Green commercial spots
