Predicting the Return of Prostate Cancer Improved by
Results from John Hopkins Study
May also help resolve the debate on when, and in
what form, secondary treatments should occur
July 2, 2009 - Cancer experts at Johns Hopkins say
a study tracking 774 prostate cancer patients for a median of eight
years has shown that a three-way combination of measurements has the
best chance yet of predicting disease metastasis (the spread of the
cancer to other parts of the body).
The new prediction method comprises these three
elements:
1. the length of time it takes for PSA
(prostate-specific antigen) to double, 2. Gleason score (a numeric indicator of prostate cancer
aggressiveness as seen under the microscope), and
3. the interval between surgical removal of the
prostate and the first detectable PSA level.
According to Johns Hopkins investigators, combining
these three measurements more accurately estimates risk that the cancer
has spread than do other methods and should help determine which
patients may benefit from additional therapy when PSA levels rise after
surgery to remove the prostate.
Findings from the study presented at the June 2009
annual meeting of the American Society of Clinical Oncology (ASCO) may
also help resolve the debate on when and in what form secondary
treatments should occur.
"There is much debate on whether to prescribe
immediate treatment for a man whose PSA begins to rise after he has had
prostate cancer surgery, or to delay it," says Emmanuel Antonarakis,
M.D., Johns Hopkins Kimmel Cancer Center investigator.
"Studies suggest that most men live the same length
of time overall whether they receive therapy at the first sign of a
rising PSA or wait until the cancer has spread to other sites."
After reviewing the records of 774 men whose PSA
rose after surgery to remove the prostate, the researchers found that
Gleason score and two measurements for PSA were the strongest risk
factors for prostate cancer metastasis.
● Men with Gleason scores in the highest range,
between eight and 10, were twice as likely to develop metastatic cancer.
● In men whose PSA became detectable within three
years after surgery, cancer was more than three times more likely to
spread to other organs.
● Finally, men whose PSA doubled the fastest,
within three months, were more than 20 times more likely to develop
metastatic cancer than men whose PSA look longer than 15 months to
double.
For men enrolled in the study, it took a median of
10 years for the disease to reappear on imaging scans.
"The 10-year average will not apply to every man,
so we wanted to know what factors put men at higher risk for their
cancer progressing earlier," says Mario Eisenberger, M.D., professor of
oncology at the Johns Hopkins Kimmel Cancer Center.
An increase in PSA, or prostate specific antigen,
occurs in approximately 20 percent to 30 percent of men after surgery to
remove the cancerous prostate, says Antonarakis.
In these patients, the newly emerging prostate
cancer cells are rarely detectable on imaging scans. When faced with the
likelihood that their cancer has spread, many men opt to undergo hormone
therapy, which blocks testosterone production, a fuel for prostate
cancer.
The side effects, which mimic those of menopausal
women, include hot flashes, night sweats, osteoporosis, metabolic
syndrome and coronary disease, and can be debilitating, says Antonarakis.
Besides immediate hormone therapy, other options
for men whose PSA is rising are to use hormone therapy intermittently,
enroll in clinical trials testing experimental therapies or combinations
of them, or to "watch and wait" until imaging scans can locate
metastatic disease.
Background Information:
Data on the prostate cancer patients involved in
this study were collected from a database maintained by Patrick C.
Walsh, M.D., at the Johns Hopkins Brady Urological Institute. The
information spans nearly 20 years of patient records at Johns Hopkins.
The research was funded by the National Cancer
Institute, the Prostate Cancer Foundation, and the Department of Defense
Prostate Cancer Research Program.
In addition to Antonarakis and Eisenberger, the
following researchers participated in the study: Bruce Trock, Zhaoyong
Feng, Elizabeth Humphreys, Michael Carducci, Alan Partin, and Patrick
Walsh from Johns Hopkins.
July 2, 2009 - Cancer experts at Johns Hopkins say
a study tracking 774 prostate cancer patients for a median of eight
years has shown that a three-way combination of measurements has the
best chance yet of predicting disease metastasis (the spread of the
cancer to other parts of the body).
