Quantitative PSA RT-PCR for preoperative staging of prostate cancer.

BACKGROUND: The clinical value of detecting prostate specific antigen (PSA) mRNA in the peripheral blood mononuclear cell fraction of patients (pts) by standard RT-PCR assays with localized prostate cancer remains controversial. We used a quantitative RT-PCR assay to measure the PSA mRNA copy number in addition to the qualitative PSA RT-PCR and correlated the results with clinical parameters. METHODS: Total RNA was extracted from the peripheral blood mononuclear cell fraction of 115 prostate cancer pts prior to radical retropubic prostatectomy (RP) who received 3 months of neoadjuvant androgen deprivation. For quantitative RT-PCR, a PSA-like internal standard (IS) was added to each sample prior to reverse transcription and the PCR products for PSA and IS were selectively detected with fluorescent europium chelates after hybridization. Corresponding qualitative PSA-RT-PCR was performed for all samples. RESULTS: The median PSA copy number was 126 (range: 0-37988). There were no significant correlations established between qualitative or quantitative RT-PCR results and given clinical parameters. Corresponding quantitative and qualitative RT-PCR results were significantly associated (P = 0.01). CONCLUSIONS: We were unable to show any additional value of quantitative as well as qualitative PSA RT-PCR for preoperative staging of prostate cancer so far. Nevertheless, the long-term follow up of the patients has to be awaited.