Reduced circulating androgen bioactivity in patients with prostate cancer.
BACKGROUND
Previous studies on immunoreactive androgen levels in serum have revealed equivocal associations with the risk of prostate cancer (CaP). The aim of this study was to compare serum biological androgen activity between men with newly diagnosed CaP and age-matched men with benign prostatic hyperplasia (BPH).


METHODS
Caucasian men with newly diagnosed, untreated CaP (n = 101) and age-matched patients with BPH (n = 103) were investigated. Serum androgen bioactivity (ABA) levels were measured using a recently developed recombinant cell bioassay.


RESULTS
In comparison to men with BPH, CaP patients with Gleason score >or=8 (n = 16) had lower serum ABA (P < 0.05), and patients with Gleason score <or=5 (P < 0.05) or >or=8 (P = 0.07) displayed suppressed ABA levels in relation to serum testosterone. As the entire group, men with CaP (n = 101) had significantly lower serum ABA than age-matched men with BPH (n = 103): median 3.0 nM (range, 0.8-6.4 nM) versus 3.2 nM (range, 0.8-7.9 nM) testosterone equivalents, respectively (P < 0.005). By contrast, serum immunoreactive testosterone and SHBG concentrations and free androgen indices did not differ significantly between the two groups.


CONCLUSIONS
Patients with CaP have lower serum ABA than controls with BPH, and men with low or high Gleason score display suppressed circulating ABA-to-testosterone ratio. These features may reflect interaction between variables such as the degree of tumor differentiation and tumor volume with androgen metabolism.
Raivio
Taneli
T
Biomedicum Helsinki, Institute of Biomedicine, University of Helsinki, Helsinki, Finland.
Santti
Henrikki
H
Schatzl
Georg
G
Gsur
Andrea
A
Haidinger
Gerald
G
Palvimo
Jorma J
JJ
Jänne
Olli A
OA
Madersbacher
Stephan
S
D000368:Aged; D000728:Androgens / Q000097:blood*; D002277:Carcinoma / Q000097:blood*; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011470:Prostatic Hyperplasia / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood*; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013739:Testosterone / Q000097:blood
D000728:Androgens; D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D017430:Prostate-Specific Antigen