Intermittent androgen suppression in the treatment of metastatic prostate cancer

To assess the feasibility of intermittent androgen suppression in patients with metastatic prostate cancer and to quantify the improvement in the quality of life.

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.

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 hormono-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.

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.