Single-therapy androgen suppression in men with advanced prostate cancer: a systematic review and meta-analysis.
OBJECTIVE
To compare luteinizing hormone-releasing hormone (LHRH) agonists with orchiectomy or diethylstilbestrol, and to compare antiandrogens with any of these three alternatives.


METHODS
A search of the MEDLINE, Cancerlit, EMBASE, and Cochrane Library databases from 1966 to March 1998 and Current Contents to 24 August 1998 for articles comparing the outcomes of the specified treatments. The search was limited to studies on prostatic neoplasms in humans. Total yield was 1477 studies.


METHODS
Reports of efficacy outcomes were limited to randomized, controlled trials. Twenty-four trials involving more than 6600 patients, phase II studies that reported on withdrawals from therapy (the most reliable indicator of adverse effects), and all studies reporting on quality of life were abstracted.


METHODS
Two independent reviewers abstracted each article by following a prospectively designed protocol. The meta-analysis combined data on 2-year overall survival by using a random-effects model and; reported results as a hazard ratio relative to orchiectomy.


RESULTS
Ten trials of LHRH agonists involving 1908 patients reported no significant difference in overall survival. The hazard ratio showed LHRH agonists to be essentially equivalent to orchiectomy (hazard ratio, 1.1262 [corrected] [95% CI, 0.915 to 1.386]). There was no evidence of difference in overall survival among the LHRH agonists, although CIs were wider for leuprolide (hazard ratio, 1.0994 [CI, 0.207 to 5.835]) and buserelin (hazard ratio, 1.1315 [CI, 0.533 to 2.404]) than for goserelin (hazard ratio, 1.1172 [CI, 0.898 to 1.390]). Evidence from 8 trials involving 2717 patients suggests that nonsteroidal antiandrogens were associated with lower overall survival. The CI for the hazard ratio approached statistical significance (hazard ratio, 1.2158 [CI, 0.988 to 1.496]). Treatment withdrawals were less frequent with LHRH agonists (0% to 4%) than with nonsteroidal antiandrogens (4% to 10%).


CONCLUSIONS
Survival after therapy with an LHRH agonist was equivalent to that after orchiectomy. No evidence shows a difference in effectiveness among the LHRH agonists. Survival rates may be somewhat lower if a nonsteroidal antiandrogen is used as monotherapy.
Seidenfeld
J
J
Blue Cross and Blue Shield Association Technology Evaluation Center, Chicago, Illinois 60601-7680, USA. Jerome.Seidenfeld@bcbsa.com
Samson
D J
DJ
Hasselblad
V
V
Aronson
N
N
Albertsen
P C
PC
Bennett
C L
CL
Wilt
T J
TJ
D000726:Androgen Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects / Q000627:therapeutic use*; D017322:Clinical Trials, Phase II as Topic; D004054:Diethylstilbestrol / Q000009:adverse effects / Q000627:therapeutic use*; D018450:Disease Progression; D018572:Disease-Free Survival; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists*; D006801:Humans; D008297:Male; D009919:Orchiectomy; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000628:therapy*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D012680:Sensitivity and Specificity; D016019:Survival Analysis
D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D007987:Gonadotropin-Releasing Hormone; D004054:Diethylstilbestrol