Possible mechanism of dexamethasone therapy for prostate cancer: suppression of circulating level of interleukin-6.
BACKGROUND
Glucocorticoids may have favorable effects on prostate cancer patients showing clinical and/or biochemical failure after androgen ablation. The efficacy and mechanisms of dexamethasone therapy as possible alternative endocrine therapy were investigated.


METHODS
Twenty five patients with prostate cancer treated by androgen ablation and showing a steady increase in serum prostate specific antigen (PSA) were treated with low-dose dexamethasone.


RESULTS
Of 25 patients, 11 demonstrated 50% or more decline of serum PSA and 9 showed improvement of pain on dexamethasone therapy. Of 8 patients who responded to dexamethasone therapy, 5 had 80% or more decrease in serum interleukin-6 (IL-6). In contrast, none of 8 non-responders showed remarkable IL-6 suppression. Response of PSA was not correlated to the changes in serum dehydroepiandrosterone, dehydroepiandrosterone sulfate, or androstendione.


CONCLUSIONS
Significant suppression of serum IL-6, probably through inhibition of androgen-independent activation of androgen receptor, may be one of the mechanisms for the effect of dexamethasone therapy in prostate cancer patients with progressive disease.
Department of Urology, Graduate School of Medicine, Chiba University, Chiba, Japan. akakura@tkn-hosp.gr.jp
Koichiro
K
Akakura
Hiroyoshi
H
Suzuki
Takeshi
T
Ueda
Akira
A
Komiya
Tomohiko
T
Ichikawa
Tatsuo
T
Igarashi
Haruo
H
Ito
D000230:Adenocarcinoma / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D000726:Androgen Antagonists / Q000627:therapeutic use; D003907:Dexamethasone / Q000627:therapeutic use*; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D013739:Testosterone / Q000097:blood; D016896:Treatment Outcome
D000726:Androgen Antagonists; D005938:Glucocorticoids; D015850:Interleukin-6; D013739:Testosterone; D003907:Dexamethasone; D017430:Prostate-Specific Antigen