PSA Testing Value Supported by Some, Others Critical

Recent news left millions of older American men confused about whether their annual PSA test was needed, and whether its results could be trusted.

But according to experts representing two leading medical groups, rumors of the demise of the PSA test may be premature.

The researcher who first identified the prostate-specific antigen (PSA) blood test, used for nearly two decades to screen men for prostate cancer, commented that the test had become "all but useless."

The Journal of Urology presented Stanford University's Dr. Thomas Stamey's opinion that the PSA test is now more likely to spot benign prostate enlargement or very slow-moving malignancies than "significant," aggressive cancers, raising risks for misdiagnosis and unnecessary surgeries.

However, Dr. Durado Brooks, director of prostate and colorectal cancer at the American Cancer Society (ACS), notes that "Dr. Stamey's article is countered by a wealth of other literature, so there's a lot of dispute right now among experts as to the level of value PSA testing offers."

Dr. Brooks believes PSA screening remains "a useful test, in terms of detecting prostate cancer in its early stage."

Screenings Detect Prostate Cancer

The PSA test, which measures blood levels of a compound secreted at higher levels as prostates enlarge, may well be a victim of its own success. Experts generally agree that when the test was first put into widespread use in the 1990s, it picked up a lot of advanced cancers that had previously been missed.

But as annual screenings have become more commonplace, PSA screening is now detecting much smaller cancers - many of them slow-growing and worthy of "watchful waiting" rather than more radical prostate-removing surgery.

What is needed, according to Dr. Brooks, are improvements to the existing PSA test "so that we can differentiate those 'bad actors' - prostate cancers that are more likely to be aggressive and to cause problems - from the indolent [slow-growing] tumors that are often found."

Dr. J. Brantley Thrasher, chairman of urology at the University of Kansas Medical Center and a spokesman for the American Urological Association, agrees with Dr. Brooks that the PSA test needs to be refined, not discarded.

"The fact of the matter is that death rates from prostate cancer have dropped precipitously from the 1990s," he notes, although there is no clear evidence that decline is due to PSA-linked early detection.

"What we're trying to do now is find better markers, tweaking PSA to make it better," he explains.

"What bothers me a little bit, especially in the lay press, is that when we start to see a little controversy around something like PSA screening, people out there will say 'Well, there's no use for PSA, don't even get one,'" he remarks.

"Then I worry that we'll go back to the situation we had 10 or 15 years ago, where we are seeing a lot of advanced-cancer patients walking through the door, crippled with bony metastases because they're not finding it till it's very late, and we don't have anything to offer them."

Dr. Thrasher points out that, despite better early detection, prostate cancer is still the second leading cause of cancer death in men, killing more than 30,000 US males each year.

According to both Drs. Thrasher and Brooks, Dr. Stamey's dismissal of the PSA test came as no real surprise, since debate has simmered among urologists and cancer specialists for years as to the exam's continued efficacy in spotting cancers worthy of aggressive treatment.

"It's always been a controversial issue," Dr. Thrasher says, "because PSA can be elevated for a number of reasons besides cancer," including the benign prostate enlargement that occurs naturally as men age.

Studies Build on PSA Test Success

The challenge for researchers is to find better blood markers, to make the test more specific, Dr. Thrasher says. "Almost every quarter I'm seeing literature coming out with new molecular markers," he says. "I'm truly convinced that we're going to come up with something that - either combined with PSA, a PSA [variant], or by itself - will be better."

In the meantime, the ACS continues to recommend that physicians offer annual PSA screening, plus a digital rectal exam (DRE), to all normal-risk male patients over 50 years of age.

According to Dr. Brooks, the challenge for patients is to "understand the benefits and the limitations of the PSA test and decide for themselves, in consultation with their physicians, exactly what they want to do, and whether they want to be tested or not."

Always consult your physician for more information.

Online Resources

(Our Organization is not responsible for the content of Internet sites.)

American Urological Association

Centers for Disease Control and Prevention (CDC)

Healthfinder, US Department of Health and Human Services (HHS)

National Institutes of Health (NIH)

NIH 4Women.Gov on Men's Health

National Library of Medicine

January 2005

PSA Testing Value Supported by Some, Others Critical

Screenings Detect Prostate Cancer

Studies Build on PSA Test Success

Testing for Prostate Problems

Online Resources

Testing for Prostate Problems

In addition to an annual physical exam that includes blood, urine, and possibly other lab tests, the National Cancer Institute and the American Cancer Society suggest consulting your physician about these recommendations for the evaluation of the prostate gland:

DRE (digital rectal examination)
A physician or nurse places a gloved and lubricated finger into the rectum to examine the rectum and feel the prostate gland.

As recommended by your physician, DREs are usually conducted annually for men over the age of 50. Men in high-risk groups, such as African Americans, or those with a strong family history of prostate cancer, should consult their physicians about being tested at a younger age or more often.

PSA (prostate-specific antigen)
PSA is a blood test that measures the level of prostate specific antigen. PSA is a substance produced by the prostate gland, which may be found in higher amounts in men who have prostate cancer.

As recommended by your physician, the PSA test is usually done annually for men over the age of 50.

Men in high-risk groups, such as African Americans, or those with a strong family history of prostate cancer, should consult their physicians about being tested at a younger age or more often.

If the results of the DRE or PSA are unusual, your physician may repeat the tests or request other procedures. These evaluation tools may include:

transrectal ultrasound (TRUS) - a test using sound wave echoes to create an image of the prostate gland to visually inspect for abnormal conditions.

A transrectal ultrasound can show if the prostate gland is enlarged or if there are any growths in or around the prostate. Ultrasound may also be used to guide a needle for biopsies of the prostate gland and/or to guide the nitrogen probes in cryosurgery.

computed tomography scan (Also called a CT or CAT scan.) - a diagnostic imaging procedure test that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than standard x-rays.

magnetic resonance imaging (MRI) - a diagnostic test that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.

radionuclide bone scan - a nuclear imaging method that helps to show whether the cancer has spread from the prostate gland to the bones. The test involves injecting a radioactive material into a vein that helps to locate diseased bone cells throughout the entire body.

(lymph node and/or prostate) biopsy - a procedure in which tissue samples are removed (with a needle or during surgery) from the body for examination under a microscope; to determine if cancer or other abnormal cells are present.

The diagnosis of cancer is confirmed only by a biopsy.

Always consult your physician for more information.