Failure to achieve castrate levels of testosterone during luteinizing hormone releasing hormone agonist therapy: the case for monitoring serum testosterone and a treatment decision algorithm.
OBJECTIVE
We report the failure to achieve a castrate level of testosterone associated with 3-month depot luteinizing hormone releasing hormone (LH-RH) agonist therapy, which to our knowledge is a previously unrecognized outcome.


METHODS
We prospectively enrolled in our study 38 men with prostate cancer on 3-month depot LH-RH agonist therapy. We monitored total serum testosterone and prostate specific antigen every 28 days beginning 90 days after the last depot LH-RH agonist injection. Data were analyzed with castrate testosterone defined as less than 50 and 20 ng./dl. or less.


RESULTS
Using the 50 and 20 ng./dl. definitions of castrate testosterone 2 (5%) and 5 (13%) of the 38 men, respectively, failed to achieve castrate testosterone. A patient with a nadir testosterone of 70 ng./dl. subsequently underwent orchiectomy and testosterone decreased to 10 ng./dl. thereafter.


CONCLUSIONS
A small but potentially important subgroup of men on depot LH-RH agonist therapy fail to achieve a castrate level of testosterone. Our findings support monitoring testicular response when LH-RH agonist therapy is initiated.
Oefelein
M G
MG
Case Western Reserve University, Cleveland, Ohio 44106, USA.
Cornum
R
R
D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000627:therapeutic use*; D015992:Body Mass Index; D003657:Decision Making; D003692:Delayed-Action Preparations; D005500:Follow-Up Studies; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000819:agonists* / Q000627:therapeutic use; D006801:Humans; D016729:Leuprolide / Q000008:administration & dosage / Q000627:therapeutic use*; D016015:Logistic Models; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009919:Orchiectomy; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D013737:Testis / Q000187:drug effects; D013739:Testosterone / Q000037:antagonists & inhibitors / Q000097:blood*; D017211:Treatment Failure
D018931:Antineoplastic Agents, Hormonal; D003692:Delayed-Action Preparations; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D017430:Prostate-Specific Antigen; D016729:Leuprolide