SAN ANTONIO The Southwest Oncology Group (SWOG) has announced
the start of the first major phase III trial to compare the
chemotherapy combination of docetaxel (Taxotere) and estramustine
phosphate (Emcyt) with the commonly used combination of mitoxantrone
(Novantrone) and prednisone for the treatment of advanced,
hormone-refractory prostate cancer.
Patient enrollment is underway, and approximately 660 men are being
recruited for the trial, which is being initiated by SWOG and funded
by the National Cancer Institute in collaboration with the Cancer and
Leukemia Group B and North Central Cancer Treatment Group.
Results of phase I/II studies have shown the combination of docetaxel
and estramustine to be very active and well tolerated in patients
with hormone-refractory prostate cancer, SWOG said in a news release.
The encouraging response rates seen thus far with the
combination of docetaxel and estramustine provide hope that using a
tolerable, more effective combination may prolong life in this group
of difficult-to-treat patients, said SWOG study chair Daniel P.
Dr. Petrylak is assistant professor of medicine, Columbia College of
Physicians and Surgeons, and director of the Genitourinary Oncology
Program, Columbia Presbyterian Center of New York-Presbyterian
Hospital, the site where this treatment regimen was developed and
first studied. The primary objectives of the study are to determine
if the docetaxel/estra-mustine combination improves overall survival
and progression-free survival when compared with the
mitoxantrone/prednisone combination, and to compare toxicities
related to the two treatments. Other objectives include assessments
of the decline of prostate-specific antigen (PSA) levels and of
quality of life among both treatment groups.
While prior clinical trials using single-agent chemotherapy have
yielded objective response rates of 10% to 20% with subjective or
stable response rates in another 20% to 40% of patients, no single
agent or combination treatment has demonstrated a survival benefit
for advanced, hormone-refractory prostate cancer patients in phase
III trials. The reported survival rate in these trials has been less
than a year, ranging from 5 to 11 months.
Palliative benefit can be achieved with the administration of
mitoxantrone with corticosteroids; however, there is no evidence that
survival is prolonged with this therapy. There is an obvious
need for new therapies based on novel methods of inhibiting cancer
growth, he said.
For the present phase III study, participants will be randomized at
the SWOG Coordinating Center to receive one of two treatment
regimens: oral estramustine taken three times daily for 5 days
combined with intravenous docetaxel administered on the second day of
treatment; or intravenous mitoxantrone administered every 3 weeks
with twice-daily oral prednisone taken for 3 consecutive weeks. A
maximum of 12 cycles of either treatment regimen will be administered.
For more information about this study (S9916), contact the National
Cancer Institutes toll-free Cancer Information Service (CIS) at