Lassen des veränderungen des prostata-spezifischen antigen- (PSA-) spiegels nach prostatastanzbiopsie rückschlüsse auf das pathologische ergebnis zu?

Introduction: Diagnostic biopsy of the prostate is known to cause elevation of serum prostate-specific antigen (PSA) levels. The aim of this prospective study was to look at a potential correlation between the degree of postbiopsy changes of the serum total and free PSA-levels and the free-to-total (f/t) PSA-ratio regarding histological diagnosis. Material and methods: A total of 79 consecutive patients suspicious for prostate cancer (PCA) with a total PSA < 50 ng/ml were included. Exclusion criteria were any signs of prostatitis or prostate needle biopsy within the last 3 months. PSA was measured using an ultra-sensitive enzyme immunoassay. Serum total and free PSA-levels were taken immediately before and 60 minutes after biopsy. Pre- and postbiopsy levels of total and free PSA as well as f/t PSA-ratio were compared in respect of final histology diagnosis. Results: 86 series of biopsies were performed in 79 patients. 38 biopsies revealed PCA, 48 benign prostatic hyperplasia (BPH). Final diagnosis after repeated biopsies was PCA and BPH in 43 cases each. Overall, the mean total PSA was rising from 18.39 ng/ml to 107.8 ng/ml, mean free PSA from 3.43 ng/ml to 33.7 ng/ ml and mean f/t PSA-ratio from 18.1% to 52.0%. There was no correlation between increase of any of parameters and number of biopsy cores (4-51). Total PSA and free-to-total PSA-ratio before the biopsy and free-to-total PSA-ratio after the biopsy revealed to be statistically significant changed between patients with PCA and those with BPH. Conclusion: Analysis of postbiopsy PSA-parameters does not provide additional information compared to the pre-biopsy PSA values as conventionally applied. Post-biopsy PSA levels do not correlate with false negative biopsy result and thus do not add clinically valuable information concerning the decision for repeated biopsies in negative results.