Intermittent androgen deprivation after PSA-complete response as a strategy to reduce induction of hormone-resistant prostate cancer

Objectives. The increasing interest in exploring the use of intermittent androgen deprivation in prostate cancer has prompted a retrospective review of patients who elected to stop treatment. Methods. Case records were reviewed. Results. Twenty patients after 3 to 48 months (median 12) of endocrine therapy elected to stop therapy. Thirteen subsequently relapsed after a median observation of 9 months. Seven of 20 patients continue progression-free for 9 to 42 months (median 33). After second-line therapy, 75% of patients with a relapse remain progression-free at 2 years. Progression-free survival was higher in patients at Stage MO (82% at 1 year) versus M+ (29% at 1 year). Conclusions. With 10 of 13 patients demonstrating an ongoing second PSA response, 45% of patients showing no progression, and 85% alive at 3 years, these results support findings from previous publications that suggest that there are no major risks with use of intermittent hormone therapy. However, in the future, there is an urgent need that such studies should be randomized and done in the context of audit-based research and development programs. The resources released could then be invested with respect to further improvements in treatment of prostate cancer, possibly considering such a combined approach with immunotherapy as an alternative to surgery or radiotherapy for early disease in elderly patients with long PSA-doubling time. Copyright 1997 by Elsevier Science Inc.