Researchers at Johns Hopkins and its
Brady Urological
Institute have identified three risk factors and
developed a simple reference tool that doctors can use to
determine who is at high risk of death after prostate
cancer recurrence following surgery. The new tool — a
set of tables that assess a combination of blood tests, the
surgical pathology results and time following surgery
— can be used to tell which men with recurring cancer
after surgery are most likely to die from their renewed
disease and would benefit from further treatment.
"We identified three risk factors associated with
death from prostate cancer after recurrence that may allow
doctors to distinguish early on between those who need
further treatment versus those who are relatively safe and
can be carefully watched," said Stephen J. Freedland,
instructor of urology at Johns Hopkins and lead
investigator of the report published in the July 27 issue
of the Journal of the American Medical Association.
If discovered early through screening, prostate cancer
is treatable and is often cured by a surgical procedure
called radical prostatectomy. However, as many as one-third
of those who undergo surgery will eventually show signs
that the cancer has recurred, Freedland said.
The risk factors are based on:
The amount of time, in months, it
takes the level of prostate specific antigen, or PSA, in
the blood to double after surgery. The shorter the time,
the higher the risk.
The elapsed time, in years, from
surgery to recurrence as measured by the PSA test. Again,
the shorter the time, the higher the risk.
The Gleason score (two to 10), a
microscopic measurement of prostate cancer aggressiveness
when viewed under a microscope. Higher scores reflect more
aggressive tumors. An additional finding was that time to
death after recurrence for patients in the low-risk group
was quite long, often much longer than 16 years, Freedland
said.
To identify the risk factors, the researchers studied
379 patients treated with radical prostatectomy at Johns
Hopkins between 1982 and 2000 who had biochemical (PSA)
recurrence signs of prostate cancer revealed in blood tests
and had at least two PSA tests after recurrence that were
separated by at least three months.
The researchers found that the time for the PSA to
double, the time from surgery to recurrence and the Gleason
score were significant risk factors for predicting time to
death from prostate cancer recurrence and that patients
could be divided into either a high-risk or a low-risk
group. The categories include PSA doubling time, Gleason
score and time from surgery to biochemical recurrence.
For example, patients with a PSA doubling time of less
than three months (23 patients) had a median survival of
six years. Patients with a PSA doubling time of less than
three months, biochemical recurrence three or fewer years
after surgery and a Gleason score of eight to 10 (15
patients) had a median survival of three years. However,
patients with a PSA doubling time of 15 months or more and
a biochemical recurrence more than three years after
surgery (82 patients) had a 100 percent survival. Using
these three risk factors, the researchers then constructed
tables to estimate the risk of prostate cancer-specific
survival at five, 10 and 15 years after biochemical
recurrence.
"We hope the tables will be useful to patients and
their physicians for assessing the risk of death from
prostate cancer following recurrence after surgery and
guide the need for additional treatments," Freedland
said.
The research was supported by the National Cancer
Institute, Prostate Cancer Foundation, U.S. Department of
Defense, American Foundation for Urologic Disease and
American Urological Association. Other authors of the study
are Alan Partin, Patrick Walsh, Mario Eisenberger, Leslie
Mangold and Elizabeth Humphreys, all of Johns Hopkins; and
Frederick J. Dorey, of the University of Southern
California.