Despite recent claims by some urologists that
measuring the blood protein prostate-specific antigen may
not be effective in predicting risk of prostate cancer, a
Johns Hopkins study of more than 2,000 men confirms that
PSA remains the best measure of the likelihood of cancer
recurrence after surgery.
Results of the study, published in the October issue
of The Journal of Urology, demonstrated that men
with high PSA levels prior to prostate removal surgery were
significantly more likely to have advanced clinical stages
of cancer, evidence of higher grade cancers in surgically
removed tissue and spread of cancer cells beyond the
prostate. In addition, increasing PSA was significantly
associated with increased risk of cancer recurrence after
surgery, even in men with lower PSA levels prior to
The study was led by Stephen J. Freedland, clinical
instructor of urology, and Alan W. Partin, professor and
chair of urology at Johns Hopkins'
"In our study, PSA levels measured before prostate
removal surgery were significantly associated with the risk
of recurrent cancer after surgery," Freedland said. "These
data support the notion that PSA remains the best available
prostate cancer tumor marker. It certainly suggests that
the PSA era is alive and well."
PSA is a protein produced by cells of the prostate
gland. Prostate cancer can increase PSA, so the higher the
PSA level, the greater the likelihood that a patient has
prostate cancer. Also, higher PSA values generally reflect
larger, more aggressive cancers. Freedland acknowledged
that because PSA provides physicians with a measure of a
patient's prostate health at a single point in time, it's
"far from perfect." However, he said, "it's better than
anything else we have."
"As a screening tool, PSA has done what we wanted it
to do," Freedland said. "It detects advanced disease early
and reduces the likelihood of metastatic disease."
For the study, Freedland and colleagues reviewed
patient records for 2,312 men who had prostate removal
surgery at Johns Hopkins between 1992 and 2004. All
operations were performed by Patrick C. Walsh, professor
and former chair of Urology. The research team compared the
association between preoperative PSA and the risk of cancer
recurrence after surgery.
During an average follow-up of five years, 211 men (10
percent) had signs of recurrent cancer. Higher PSA levels
prior to surgery were significantly associated with
increased risk of cancer after surgery. Compared to men
with PSA levels less than 10 nanograms per milliliter, men
with PSA values between 10 and 19.9 nanograms per
milliliter were more than three times more likely to
develop cancer after surgery. Men with PSA levels of 20
nanograms per milliliter or greater were more than five
times more likely to develop cancer after surgery than
those with low PSA levels.
Even in men with PSA values of less than 10 nanograms
per milliliter, increasing PSA was significantly associated
with increased risk of cancer after surgery. For each
two-point increase in PSA, the risk of cancer after surgery
"From our study and others, it is clear that a single
PSA value is an extremely useful measure of a patient's
risk of progression after surgery," Freedland said.
"However, looking at how quickly the PSA increases over
time is likely to be even more informative than a single
The study was supported by the National Institutes of
Health, the Department of Defense and the American
Foundation for Urological Disease/American Urological
Co-authors were Leslie A. Mangold and Walsh.