Risk Of Advanced Cancer After Radical Prostate Surgery
Formula May Help Patients and Physicians Choose Further Therapy
May 15, 1999. While prostate removal cures most men of their
prostate cancer, more than a third show a rise in their prostate specific
antigen (PSA) levels in the 10 years following surgery, an early sign
that cancer may be returning. Now, in the largest and longest study of
its kind, urologists at Johns Hopkins have developed a method for assessing
the risk these men have for developing metastatic cancer.
"The first thing patients want to know after their PSA rises
following surgery is how long they have to live," says Patrick Walsh,
M.D., Hopkins' chief of urology, who removed the prostates of the 1, 997
patients in the study. "And the first thing doctors want to know
is what type of follow-up treatment the patient needs. Up until now, there
hasn't been any sure way to know."
In the most extensive follow-up study on
the natural course of prostate cancer after surgery, Walsh and his colleagues
compiled 10,000 patient-years of data from 1982 to 1997. The men were
followed for an average of 5.3 years. From this information, Walsh's team
developed a chart physicians and patients can use to pinpoint the risk
for developing metastatic cancer, which in men with prostate cancer typically
invades the bones.
"Doctors used to say, You've recurred,
but we aren't sure what that means," says Alan Partin, Ph.D., a co-author
on the study, which appeared in the May 5, 1999, Journal of the American
Medical Association [see link in sidebar]. "Now they can say,
You've recurred, and we know your risk for developing advanced cancer."
While outcomes depend partly on whether
removal of the prostate is appropriate for the patient in the first place
and on quality of surgery and after care, the formula pinpointed by this
Hopkins study should hold across the board, wherever the surgery is done.
The formula cannot predict how many men will experience recurrence after
surgery at other medical centers. Butif recurrence happens, what counts
is not where the surgery was done but what the disease is doing
Time Till PSA Rise, PSA Doubling Time
The chart places men into different risk
groups using three common measures: the so-called Gleason score of the
removed prostate (a measure of the cancer's severity and aggressiveness);
timing of the rise in PSA level (either before or after two years post-surgery);
and the length of time it took the PSA level to double (either greater
or less than 10 months).
A man in the lowest risk group (with a
moderately severe tumor, PSA recurrence after two years post-surgery,
and PSA doubling time greater than 10 months) has a 95 percent chance
of being metastases-free three years after the PSA recurrence; an 86 percent
chance at five years; and an 82 percent chance at seven years.
"When men see their PSA levels rise
again, they think that means the cancer is back and they need to get treated
aggressively right away. But that isn't always the case," says Mario
Eisenberger, M.D., a Hopkins oncologist and study co-author. "Patients
may live for years without having the cancer spread. This information
will better equip doctors and their patients to decide who is a candidate
for additional therapy."
The study is critical for future drug research
as well, says Partin, because it provides essential baseline data. "Before,
it was difficult to know if a drug was helping, because you couldn't be
sure what the disease would have done on its own," he says. "Now,
researchers can compare their treatment groups with our study group and
tell if their treatment is improving survival."
Other findings from the study:
Men who experienced rising PSA levels (304 out of 1,997) remained free
from metastatic cancer an average of eight years.
After developing metastatic cancer, as confirmed by imaging techniques
like bone scans, the average time to death was five years. However, men
who developed metastases eight or more years following surgery had a much
At 15 years post-surgery, a projected 82 percent of men will still be
free from metastatic cancer and considered cured.
These projections are based solely on surgery performed by Walsh's team
at Johns Hopkins.