Similar frequency of testosterone surge after repeat injections of goserelin (Zoladex) 3.6 mg and 10.8 mg: results of a randomized open-label trial.
OBJECTIVE
To investigate whether testosterone surges occur on repeat injections of 3.6 or 10.8 mg goserelin (Zoladex) depot and, if so, their extent.


METHODS
Men with prostate cancer for whom hormonal therapy was indicated were randomized to open-label goserelin 3.6 mg every 28 days (n = 129) or 10.8 mg every 84 days (n = 118) for 48 weeks. Serum testosterone and luteinizing hormone levels were measured before repeat injection on day 1 of each treatment cycle and then on days 4 and 8. Surges were defined in three ways: type 1, simultaneous increase in both testosterone and luteinizing hormone to within the age-specific normal range; type 2, increase in testosterone to within the age-specific normal range; and type 3, elevation in testosterone from less than to greater than the castrate level (greater than 18.5 ng/dL).


RESULTS
Most patients did not experience a testosterone surge. Two patients (1.8%) in the 10.8-mg group had a type 1 surge after one repeat injection and two (1.6%) in the 3.6-mg group had a type 2 surge after one repeat injection. Type 3 surges occurred after one or more repeat injections in 34 (27.0%) and 20 (17.7%) patients in the 3.6-mg and 10.8-mg groups, respectively (P = 0.065); the mean surge (+/- standard deviation) was 11.2 ng/dL (+/-13.5) and 17.3 ng/dL (+/-24.6), respectively. No patient with a testosterone surge had clinical symptoms of a tumor flare reaction.


CONCLUSIONS
The testosterone levels were consistently maintained within the castrate range (18.5 ng/dL or less) in most (77.4%) patients receiving long-term 3.6 mg or 10.8 mg goserelin.
Zinner
Norman R
NR
Western Clinical Research Inc., Torrance, California, USA. wewedoc@aol.com
Bidair
Mohamed
M
Centeno
Arthur
A
Tomera
Kevin
K
D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000627:therapeutic use*; D017273:Goserelin / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D010166:Palliative Care; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D013739:Testosterone / Q000097:blood*
D018931:Antineoplastic Agents, Hormonal; D017273:Goserelin; D013739:Testosterone; D007986:Luteinizing Hormone