Early postoperative peripheral blood reverse transcription PCR assay for prostate-specific antigen is associated with prostate cancer progression in patients undergoing radical prostatectomy

Abstract

Preoperative peripheral blood reverse transcription-PCR (RT-PCR) for prostate-specific antigen (PSA) [RT-PCR-PSA] is not associated with an increased risk of progression after radical prostatectomy. We tested the hypothesis that early postoperative peripheral blood RT-PCR-PSA would detect prostate cancer cells persisting in the circulation that would be associated with disease progression. The study group consisted of 145 consecutive patients who underwent radical prostatectomy for clinically localized disease (median follow-up, 54.5 months) for whom pre- and postoperative peripheral blood samples were available. RT-PCR-PSA was performed on preoperative and postoperative peripheral blood specimens. Pre- and postoperative RT-PCR-PSA were positive in 27% and 12%, respectively, of patients. Most (64%) preoperative RT-PCR-PSA-positive patients converted to a negative RT-PCR-PSA status after prostate removal (P < 0.001). Whereas preoperative RT-PCR-PSA was not associated with prostate cancer characteristics or outcome, a positive postoperative RT-PCR-PSA assay was associated with extracapsular extension (P = 0.044) and seminal vesicle involvement (P = 0.024). Furthermore, postoperative RT-PCR-PSA was an independent predictor of disease progression (P = 0.027). In patients who experienced disease progression, postoperative RT-PCR-PSA was associated with a more aggressive pattern of failure (P = 0.005). Whereas a significant number of patients with clinically localized prostate cancer have prostate cells detectable preoperatively by RT-PCR-PSA circulating in their blood, most of these cells are clinically insignificant because the majority of these patients convert to RT-PCR-PSA-negative status and maintain disease-free status after prostate removal. In contrast, postoperative RT-PCR-PSA detection of prostate cells in the peripheral blood is associated with established markers of aggressive prostate cancer and is an early independent predictor of disease progression, presumably because of an association with established micrometastatic disease.