Intermittent androgen suppression in the treatment of metastatic prostate cancer

Background: To assess the feasibility of intermittent androgen suppression in patients with metastatic prostate cancer and to quantify the improvement in the quality of life. Methods: Forty-three patients with M1 b prostate cancer were treated by intermittent hormonal deprivation using luteinizing hormone-releasing hormone (LHRH) analogue alone (n = 11), or associated with an antiandrogen (n = 32). The prospective nonrandomized study required an initial therapy period of 12 months with a stable biological response during 6 months (PSA, testosterone). Treatment was resumed when the serum PSA value recovered to 20 ng/ml, or when local failure or new bone metastasis occurred. The assessment of quality of life was carried out using the EORTC QLQ-C30. Results: The mean follow-up time was 43.7 months. After the initial 12 months of androgen suppression, one patient with a minimal disease was off-therapy with a follow-up of 18 months. For the 42 other patients, the mean off-therapy period was 6.7 months. In the second therapy period (9-12 months), 7 patients were hormone-independent and died with a mean survival time of 27 months; 35 patients were responders. The mean off-therapy length in the second cycle was short (3.8 months). After this time, androgen suppression therapy was reintroduced permanently, but 10 patients were hormono-independent, No difference was observed in the EORTC QLQ-C30 between therapy and off-therapy periods, only a rapid decrease in adverse events due to the hormonal deprivation was reported in all cases during the off-therapy period. Conclusions: Intermittent androgen suppression in patients with M1 b prostate cancer could be associated with a significant period off-therapy in the first cycle (55.8%), and with a chance of second hormone response. But in the second cycle, the off-therapy period length was short and required a careful follow-up. Copyright (C) 2000 S. Karger AG, Basel.