Background: Prostate-specific antigen (PSA) is used as an outcome measure for relapsed disease in prostate cancer.
Nonetheless, there are considerable concerns about its indiscriminate use as a surrogate endpoint for cell growth or survival. We hypothesized that treatment with a luteinizing hormone releasing hormone (LHRH) analog would decrease PSA levels even in the absence of malignant disease.
Methods: We determined testosterone and PSA levels in 30 healthy volunteers after a single intramuscular injection of a LHRH depot formulation. Testosterone and PSA levels were quantified by radioimmunoassay and electrochemi-luminescence immunoassay, respectively.
Results: After an initial flare-up during the first 3 days testosterone decreased reaching castration levels in 18 of the 30 young men (60%). After the nadir on day 28, testosterone levels increased to normal again. Changes in PSA paralleled those of testosterone. Castration reduced PSA levels by 29% (95% CI 19%-39%) compared to baseline (p< 0.0001).
Conclusions: LHRH superagonists decrease PSA levels by testosterone deprivation. Conferring these findings to tumor patients, decreases in PSA after treatment with LHRH analogs might not only reflect disease regression but also a direct testosterone mediated effect on PSA. Thus, PSA levels should be cautiously interpreted when patients receive hormonal therapy.
Written by:
Wenisch JM, Mayr FB, Spiel AO, Radicioni M, Jilma B, Jilma-Stohlawetz P. Are you the author?
Department of Clinical Pharmacology, Division of Immunohematology, Medical University of Vienna, Vienna, Austria.
Reference: Clin Chem Lab Med. 2014 Mar 1;52(3):431-6.
doi: 10.1515/cclm-2013-0535
PubMed Abstract
PMID: 24423580
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