Abstract

Intermittent androgen blockade (IAB) for advanced prostate cancer was initially intended to prolong the overall period of androgen dependence, the time course of the disease until progression and to improve the quality of life. This study was undertaken to assess the feasibility of IAB and to present the clinical outcome of patients who were treated with IAB.

Fifteen previously untreated patients with locally advanced or metastatic prostate cancer were treated using IAB. Hormonal treatment options were explained and with the patients' consent IAB was instituted to the patients, especially who wish to participate in an international IAB study protocol. Maximum androgen blockade was initiated for 3 months. Hormonal therapy was ceased in patients whose PSA falls >80% of the initial value or <4 ng/ml. At the off hormone therapy period patients were followed clinically and with PSA. Therapy is restarted when PSA is >10 ng/ml or the patient is symptomatic; or when PSA is >20 ng/ml and the patient is asymptomatic. Time to tumor progression, progression free survival, treatment free period and quality of life issues were evaluated.

The patients received mean 2.5 cycles (range, 1-8) of hormone therapy. The mean time to PSA nadir or >80% decrease was 8.8 weeks (range, 4-14). The mean of treatment period was 55% for the entire therapy period. After a mean of 20.8 months, 4 (57%) of the7 patients with metastatic disease and 4 (50%) of the 8 patients with locally advanced disease progressed to an androgen independent state. After a median 40 months follow-up, progression-free and overall survival were 22±3.4 months (range, 8-46) and 41.6±4 months (range, 18-72), respectively. Ten (66%) patients had reported an increase of libido and recovery of sexual function during off therapy periods, after a median 8 weeks following cessation of androgen blockade.