Changes in molecular forms of prostate-specific antigen during treatment with finasteride.
OBJECTIVE
To study the influence of finasteride treatment on the molecular forms of prostate-specific antigen (PSA) in patients with benign prostatic hyperplasia (BPH).


METHODS
Total PSA, free PSA and PSA complexed to alpha1-antichymotrypsin (PSA-alpha1ACT) were measured in plasma and serum from 40 men with BPH and a total PSA of < 20 ng/mL, using in-house and commercial immunoassays, before and during treatment with finasteride (30 men) or placebo (10 men).


RESULTS
The baseline values were not significantly different between the groups, with mean (sd) total plasma PSA levels of 3.6 (4.3) and 4.8 (5.9) ng/mL in the finasteride and placebo groups, respectively. Finasteride, but not placebo, induced a significant reduction in total PSA, free PSA and PSA-alpha1ACT levels in plasma and serum (P < 0.001). However, complexed-to-total (c/t) and free-to-total (f/t) PSA ratios remained constant in both groups, both in plasma and serum, during the follow-up.


CONCLUSIONS
The decrease in total PSA after finasteride treatment results from a proportional reduction in its two major molecular forms, free PSA and PSA-alpha1ACT, which explains why the c/t and f/tPSA ratios do not change significantly despite treatment. This suggests that routine analysis of molecular forms of PSA could improve the utility of the change in total PSA associated with finasteride for the early diagnosis of prostate cancer. It also suggests that any subsequent change in both ratios, particularly an increase in c/tPSA or a decrease in f/tPSA ratio, could be considered an early sign of neoplastic degeneration rather than a therapeutic consequence.
España
F
F
Research Center and Department of Urology, La Fe University Hospital, Valencia, Spain. espanya_fra@gva.es
Martínez
M
M
Royo
M
M
Estellés
A
A
Alapont
J M
JM
Navarro
S
S
Aznar
J
J
Jiménez-Cruz
J F
JF
D000368:Aged; D000369:Aged, 80 and over; D004311:Double-Blind Method; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018120:Finasteride / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood / Q000737:chemistry*; D011470:Prostatic Hyperplasia / Q000097:blood / Q000188:drug therapy*
D004791:Enzyme Inhibitors; D018120:Finasteride; D017430:Prostate-Specific Antigen