Screening Guidelines

(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.