Molecular Forms of Prostate-specific Antigen in Malignant and Benign Prostatic Tissue: Biochemical and Diagnostic Implications

lower ratio of free prostate-specific antigen (fPSA) to total PSA (tPSA) in serum than patients with benign prostatic hyperplasia (BPH). The patterns of the intra-cellular PSA isoforms in malignant and benign prostatic tissue have been studied as potential molecular reasons for this phenomenon. Methods: Prostatic tissue samples were obtained after cystoprostatectomy from patients with bladder cancer (n 5 10), from BPH patients (transurethral resection of the prostate, n 5 10; adenomectomy, n 5 10), and from the cancerous and noncancerous parts of the same pros-tates removed surgically by prostatectomy because of PCa (n 5 20). PSA pattern was characterized by gel filtration, immunoblotting, and immunoassays for tPSA, fPSA, a1-antichymotrypsin-PSA (ACT-PSA), an