April 14 in the Journal of Clinical Oncology reported that Eric M. Horwitz, M.D., from Fox Chase Cancer Center in Philadelphia, and colleagues treated 1,554 prostate cancer patients with goserelin and flutamide (ADT) before and during radiation therapy. The men were then randomly assigned to receive no further ADT or 24 additional months of ADT. Both groups continued to receive radiation for the same period of time.

It was found that at ten years, those who received the longer term (24 months) of ADT had significantly better outcomes being defined as significantly better disease-free survival, disease-specific survival, local progression, distant metastasis and biochemical failure. However, they did not receive an extended survival benefit, the gold standard endpoint. The only exception were men with more advanced disease (Gleason scores of 8 to 10) who also received a survival benefit.

Horwitz and colleagues conclude that “Long-term androgen-deprivation therapy as delivered in this study for the treatment of locally advanced prostate cancer is superior to short-term androgen-deprivation therapy for all end points except survival.”

However, when most of us talk about using intermittent ADT we do not consider the use of only four months of ADT. Usually we recommend that the “on” period for ADT to last between 9 and 12 months, coupled with a minimal PSA during that period. This study should not discourage anyone from considering intermittent ADT.

Joel T Nowak MA, MSW