Systematic Review and Meta-analysis of Monotherapy Compared with Combined Androgen Blockade for Patients with Advanced Prostate Carcinoma

Background: The current systematic review and meta-analysis compared monotherapy and combined androgen blockade in the treatment of men with advanced prostate carcinoma. Outcomes of interest included overall, cancer specific, and progression-free survival; time to treatment failure; adverse events; and quality of life.

Methods: The literature search identified randomized trials comparing monotherapy (orchiectomy and luteinizing hormone-releasing hormone [LHRH] agonists) with combination therapy using orchiectomy or a LHRH agonist plus a nonsteroidal or steroidal antiandrogen. Dual independent review occurred. The meta-analysis used a random effects model.

Results: Twenty-one trials compared survival after monotherapy with survival after combined androgen blockade (n = 6871 patients). The meta-analysis found no statistically significant difference in survival at 2 years between patients treated with combined androgen blockade and those treated with monotherapy (20 trials; hazard ratio [HR] = 0.970; 95% confidence interval [95% CI], 0.866-1.087). The authors determined a statistically significant difference in survival at 5 years that favored combined androgen blockade (10 trials; HR = 0.871; 95% CI, 0.805-0.942). For the subgroup of patients with a good prognosis, there was no statistically significant difference in survival. Adverse effects leading to withdrawal from therapy occurred more often with combined androgen blockade. To the authors' knowledge there is little evidence published to date comparing the effects of combined androgen blockade and monotherapy on quality of life, but the single randomized trial that adequately addressed this outcome reported an advantage for monotherapy over combined androgen blockade.

Conclusions: A thorough examination of the usefulness of combined androgen blockade must balance the modest increase in expected survival observed at 5 years against the increased risk of adverse effects and the potential for adversely affecting the patient's overall quality of life.