Is Prostate Cancer Screening Still Necessary?
The current test for prostate cancer continues to spark debate. In part 1 of WebMD's 2-part series, there's important prostate cancer information that men should have.
Understanding Prostate Cancer and the PSA Exam continued...
The role of the prostate is to produce a substance that mixes with sperm to
create semen. Prostate cells also secrete a number of proteins, including
prostate specific antigen, or PSA.
"It's important to note that both normal prostate cells and malignant
prostate cells produce PSA," says Chinnaiyan.
So how does the PSA relate to prostate cancer?
Experts say a small amount of PSA is always leaked into the bloodstream.
Just how much is found in the blood is then used to determine the risk of
While it seems like a straightforward association, it's not. The reason:
According to urologist Simon Hall, MD, there are some men with a very
aggressive prostate cancer whose PSA levels are normal. Likewise, there are men
whose PSA levels are soaring but who are cancer-free. And right now, no one is
Still, he tells WebMD, "It's important for men to understand that the
PSA does not diagnose cancer; it helps to create a risk profile. It only tells
you if your risk is increased," says Hall, chairman of the department of
urology at the Mount Sinai School of Medicine in New York City. And, he says,
when interpreted properly, it can do just that.
To help further define those risks, doctors frequently perform a second exam
known as the DRE or digital rectal exam. In this test the doctor manually
examines the prostate through the rectum, checking for shape, symmetry,
hardness, and size.
The Prostate Cancer Biopsy: Your Ultimate Diagnostic
Depending on the findings of both the DRE and PSA screenings, the final
diagnostic step is frequently a biopsy or sampling of the cells inside the
prostate. In this procedure, Lepor says, 12 to 14 cores [cell samples] are
removed and tested for the presence of cancer cells and their type, size, and
aggressiveness (how fast they are growing).
The method of notating this measurement is called the Gleason score, and it
ranges from 2 (known as an incidental cancer and probably slow
growing) to 10 (which indicates a highly aggressive cancer with imminent health
But as effective as the biopsy can be in determining both risks and
treatment choices, Lepor points out that it doesn't always render clear-cut
"It's entirely possible for the sampling to pull up cells that indicate
only a moderate or even incidental cancer when right next door there could be
more aggressive cells," he says.
If the decision is then made to remove the prostate, and no more aggressive
cells are found, then the surgery might have been unnecessary. But at the same
time, he says, not doing the surgery -- and missing the aggressive cells --
could mean death.
But rather than blame the PSA for the unnecessary procedures, both Hall and
Lepor say it can aid in making the right treatment decision.
"While the PSA does not yield a cancer diagnosis on its own, together
with other pieces of information it forms a risk profile, and it is that risk
profile that can be very important when determining an individual man's course
of treatment," says Hall.