Rising PSA Levels May Sometimes Lead to Negative
Biopsies But Usually Means Cancer
News study shows nearly 70 percent with rising PSA
eventually get prostate cancer
May
18, 2011 - A man's rising PSA (prostate-specific antigen) level over
several years which had been seen as a possible warning sign of
prostate cancer has recently come under fire as a screening test
because it sometimes prompts biopsies that turn out to be normal. Thats
true, the study shows, but most are headed for prostate cancer.
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The new study shows nearly 70 percent of men who
had rising PSA levels and subsequent normal biopsies were eventually
diagnosed with prostate cancer, according to research from Northwestern
University Feinberg School of Medicine. The trend of a PSA level over
several years is called PSA velocity.
"Our findings show an elevated and rising PSA level
or velocity should lead a clinician to follow a patient more closely,
even if he has a negative biopsy," said lead investigator William
Catalona, M.D., director of the clinical prostate cancer program at the
Robert H. Lurie Comprehensive Cancer Center of Northwestern University.
"One negative biopsy isn't the end of the road."
The findings were presented May 18 at the American
Urological Association 2011 Annual Meeting. Catalona is a professor of
urology at the Feinberg School and a urologist at Northwestern Memorial
Hospital.
PSA is a substance whose elevated levels can
indicate prostate cancer but can also be caused by prostate inflammation
or enlargement or other conditions. Catalona, known as the father of the
PSA screening, was the first to show in 1991 that a simple blood test
measuring PSA levels could be used to detect prostate cancer.
For the study, Northwestern researchers looked in
their database at the history of 97 patients with a rising PSA trend (or
velocity) who had a subsequent negative biopsy. Researchers found 66
percent of patients were eventually diagnosed with prostate cancer, 20
percent had a benign prostate, 8 percent had protatitis and 6 percent
had premalignant lesions.
"This underscores the importance of using a
patient's individual PSA trend when deciding whether to pursue a
prostate biopsy," said co-investigator Gregory Auffenberg, M.D., a
resident in urology at the Feinberg School. "It's not enough to only
look at an individual PSA value when historical data is also available."
"Although specific recommendations regarding PSA
screening vary, there is general agreement that men should be informed
about the potential risks and benefits of PSA screening before being
tested," according to the National Cancer Institute.
Currently, Medicare provides coverage for an annual
PSA test for all men age 50 and older.
The research was supported in part by the
Urological Research Foundation, Prostate SPORE Grant and a Lurie Cancer
Center grant.
What is the prostate-specific antigen (PSA) test? National Cancer Institute
Prostate-specific antigen (PSA) is a protein
produced by cells of the prostate gland. The PSA test measures the level
of PSA in the blood. The doctor takes a blood sample, and the amount of
PSA is measured in a laboratory. Because PSA is produced by the body and
can be used to detect disease, it is sometimes called a biological
marker or a
tumor marker.
It is normal for men to have a low level of PSA in
their blood; however, prostate cancer or
benign (not cancerous) conditions can increase a mans PSA level. As
men age, both benign prostate conditions and prostate cancer become more
common. The most frequent benign prostate conditions are
prostatitis (inflammation
of the prostate) and
benign prostatic hyperplasia (BPH)
(enlargement of the prostate). There is no evidence that prostatitis or
BPH causes cancer, but it is possible for a man to have one or both of
these conditions and to develop prostate cancer as well.
A mans PSA level alone does not give doctors
enough information to distinguish between benign prostate conditions and
cancer. However, the doctor will take the result of the PSA test into
account when deciding whether to check further for signs of prostate
cancer.
Doctors recommendations for screening vary. Some
encourage yearly screening for men over age 50, and some advise men who
are at a higher risk for prostate cancer to begin screening at age 40 or
45. Others caution against routine screening. Although specific
recommendations regarding PSA screening vary, there is general agreement
that men should be informed about the potential risks and benefits of
PSA screening before being tested.
Currently, Medicare provides coverage for an annual
PSA test for all men age 50 and older.
May
18, 2011 - A man's rising PSA (prostate-specific antigen) level over
several years which had been seen as a possible warning sign of
prostate cancer has recently come under fire as a screening test
because it sometimes prompts biopsies that turn out to be normal. Thats
true, the study shows, but most are headed for prostate cancer.