España F, Martínez M, Royo M, Estellés A, Alapont J M, Navarro S, Aznar J, Jiménez-Cruz J F
Research Center and Department of Urology, La Fe University Hospital, Valencia, Spain.
BJU Int. 2002 Nov;90(7):672-7. doi: 10.1046/j.1464-410x.2002.03002.x.
To study the influence of finasteride treatment on the molecular forms of prostate-specific antigen (PSA) in patients with benign prostatic hyperplasia (BPH).
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).
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.
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.
研究非那雄胺治疗对良性前列腺增生（BPH）患者前列腺特异性抗原（PSA）分子形式的影响。
使用内部和商业免疫测定法，在40例总PSA<20 ng/mL的BPH男性患者中，于非那雄胺治疗（30例）或安慰剂治疗（10例）前及治疗期间，检测血浆和血清中的总PSA、游离PSA以及与α1-抗糜蛋白酶结合的PSA（PSA-α1ACT）。
两组的基线值无显著差异，非那雄胺组和安慰剂组的血浆总PSA平均（标准差）水平分别为3.6（4.3）和4.8（5.9）ng/mL。非那雄胺而非安慰剂可使血浆和血清中的总PSA、游离PSA及PSA-α1ACT水平显著降低（P<0.001）。然而，在随访期间，两组血浆和血清中的结合/总（c/t）和游离/总（f/t）PSA比值均保持恒定。
非那雄胺治疗后总PSA的降低是由于其两种主要分子形式游离PSA和PSA-α1ACT成比例减少所致，这解释了为何尽管进行了治疗，c/t和f/t PSA比值仍无显著变化。这表明对PSA分子形式进行常规分析可能会提高与非那雄胺相关的总PSA变化在前列腺癌早期诊断中的效用。这也表明这两个比值随后的任何变化，尤其是c/t PSA升高或f/t PSA比值降低，可被视为肿瘤变性的早期迹象而非治疗结果。
