ANAHEIM, CaliforniaThe timing of androgen deprivation therapy for
prostate cancer may well affect disease-specific survival, according to two
studies presented at the American Urological Association annual meeting.
Androgen deprivation therapy is the main treatment for recurrent and
metastatic prostate cancer. After an initial high response rate to the therapy,
most patients progress to androgen independence. A study from Wayne State
University, Detroit (abstract 692), found that intermittent androgen
deprivation may delay the time to androgen-independent status.
Emad Youssef, MD, and his colleagues treated 74 patients intermittently with
luteinizing hormone-releasing hormone (LHRH) agonists with or without oral
antiandrogens between January 1993 and March 2000. The indications were rising
PSA level after local treatment (n = 41), bone metastases (n = 9), local
recurrence (n = 16), and lymphadenopathy (n = 8).
Patients were treated with intermittent androgen deprivation for 1 to 6
cycles for a median of 21 months (range, 1 to 85 months) and were followed for
a median of 60 months.
The study evaluated the pattern of PSA changes with each cycle, the length
of each cycle, and the time interval between successive cycles. The time to
androgen-independent status and the androgen-independent progression rate and
its relation to the initial cause of treatment were quantified.
The main result was a progressive rise in PSA nadir with a progressive
decrease in the time between treatment cycles, Dr. Youssef reported. Median PSA
before the first cycle was 11.4 ng/mL. Median PSA nadir after each cycle
increased progressively: from 0.1 ng/mL after the first cycle to 3.3 ng/mL
after the fifth cycle.
The time interval between cycles also decreased progressively, from 9.5
months between the first and second cycles to 6 months between the third and
fourth cycles. The median time to androgen-independent status has not been
reached, he said, except for patients treated for bone metastases, where it was