Analysis of molecular isoforms of PSA and their ratios in men with PSA-relapse after radical prostatectomy

Background: The aim of this study was the longitudinal comparison of % f-PS A in patients before radical prostatectomy and after PSA relapse. Is % f-PS A a consistent tumor specific parameter ol does this ratio change during un treated tumor progression? Materials and Methods: In this study 41 out of 4 20 patients with unheated increasing PSA-progression (>0.5 ng/ml) were anal ysed. Patients with neoadjuvant or adjuvant hormonal therapy were excluded. T-PSA were f-PSA were analyzed by Immulite DPC (Diagnostic Products Coop., CA) and Abbott Axsym (Abbott Park, Il, USA). Results: Pre-operative % f-PS A ratio was 10.6 % (range 4.6-22%; Std. dev.: 4.9); T-PSA concentration was 26.4 ng/ml (range 5.5-10.2 ng/ml Std. dev.: 20.3). In men with PSA relapse after radical prostatectomy % f-PSA ratio was 14.73% (range 2.2-4.5 % Std dev.: 9.7). Repeated post-operative % f-PSA measurements resulted in 12.94 % f-PSA (range 2.7-3.8 % Std dev.: 9.9 %) with a regression of R = 0.57. Al l men with pre-operative elevated % f-PSA (> 15%) had post-operative elevat ed % f-PSA. Conclusions: The data indicates that post-operative % f-PSA is a constant tumor specific parameter in men with untreated PSA relapse after radical prostatectomy. Post-operative % f-PSA was higher compared with pre -operative % f-PSA concentrations. No correlation with Gleason score or pat hological stage was found.