Bilateral orchidectomy and flutamide versus orchidectomy alone in newly diagnosed patients with metastatic carcinoma of the prostate--an Australian multicentre trial

Abstract

Objectives: To investigate the hypothesis that maximal androgen blockade improves the outcome of patients with metastatic prostate cancer.

Patients and methods: A total of 222 previously untreated patients with metastatic prostatic cancer were entered into a randomized, double-blind, placebo-controlled trial of bilateral orchidectomy with or without androgen blockade (112 receiving flutamide and 110 a placebo) which commenced in 1985 in four Australian centres. The characteristics of the patients, e.g. age, performance status, the presence of bone pain, duration of disease and the use of prior radiation, were well balanced between the groups. Patients commenced the protocol therapy with flutamide or placebo within the 7 days preceding surgery and continued this medication for a minimum of 2 years, unless there was unequivocal evidence of tumour progression.

Results: Apart from a difference in grade 3 or 4 gastrointestinal toxicities between the flutamide and placebo arms (13% and 3%, respectively), serious or life-threatening toxicities were uncommon and equally balanced. The assessment of response in six patients (three in each arm) was inevaluable. The objective response rates were 45% and 56% in the flutamide and placebo arms, respectively. There was no difference in survival between the treatments.

Conclusions: This study was not sufficiently powerful to detect small differences in outcome (although the trend in survival favoured the placebo arm) but nevertheless failed to show any benefit for maximal androgen blockade over orchidectomy in this group of patients.