SAN FRANCISCO—If PSA rises in a prostate cancer patient after prostatectomy, should the man receive immediate androgen deprivation therapy? Two experts at the Third Annual Oncology Congress approached the question from different angles but reached essentially the same conclusion.
Speaking in favor of early ADT use, Michael Koch, MD, pointed to a number of studies suggesting a cancer-specific benefit to early therapy and concluded that early ADT should be strongly considered in populations at high risk for rapid disease progression. Taking the "con" side, Nancy Dawson, MD, said there are no reliable prospective studies showing an overall survival benefit for early ADT in all patients, but also concluded that selected high-risk patients may benefit.
Dr. Koch, who is John P. Donohue Professor of Urology at Indiana University School of Medicine, pointed to a literature review that ASCO relied on to update its practice guideline on this issue (J Clin Oncol 25:1596-1605, 2007).
The authors concluded that in patients with metastatic, recurrent, or progressive disease, immediate use vs late use (at onset of symptoms) of ADT results in a moderate decrease (17%) in relative risk for prostate-cancer-specific mortality, but this is offset by a moderate increase (15%) in risk for non-prostate-cancer-specific mortality. There was no significant advantage in overall survival for early use.
"The data are overwhelmingly positive that early ADT can decrease prostate cancer mortality; the question is whether it can decrease overall mortality, and that has to do more with how you select your patients than whether early treatment is effective," Dr. Koch said.
The best level 1 evidence for use of early ADT, Dr. Koch maintained, comes from Messing et al (N Engl J Med 341:1781-1788, 1999). In this study, 98 node-positive patients with no evidence of bone metastases were randomized after radical prostatectomy to early ADT or observation until nonserologic relapse.
Only 4 of 47 patients who received immediate ADT had failed therapy at a median of 7.1 years of follow-up, compared with 34 failures in 51 patients who received delayed therapy. "Only 50% of the failures in the delayed patients responded to hormone therapy," he stressed, adding that a study update showed a significant advantage in 10-year overall survival for early ADT (82% vs 56%).
