November 5, 2009
Does Prostate-Specific Antigen Velocity Help In Early Detection Prostate Cancer?
European Urology article discusses results from large study
The November issue of European Urology, the official journal of the European Association of Urology, features an article focusing on prostate specific antigen (PSA) velocity and early cancer detection. It has been suggested that changes in PSA over time aid prostate cancer detection.It is argued that a rapidly rising PSA may indicate a greater risk of diagnosis of prostate cancer even if PSA levels are low. Some guidelines do incorporate PSA velocity cut points as an indication for biopsy. Professor A.J. Vickers of the Memorial Sloan-Kettering Cancer Center, Department of Medicine in New York (US): "Thus our aim was to evaluate whether PSA velocity indeed enhances the prediction of biopsy outcome in a large, representative, population-based cohort."
There were 2742 screening-arm participants with PSA <3 ng/ml at initial screening in the European Randomized Study of Screening for Prostate Cancer (ERSPC) in Rotterdam (NL) or Göteborg (SE) who were subsequently biopsied due to elevated PSA.
Professor Vickers: "Our study has several strengths. It included a very large number of men in a randomized trial, who were therefore subject to highly standardized testing and follow-up procedures. We avoided verification bias and addressed the key question of whether PSA velocity adds information beyond that provided by PSA alone. We also used decision analysis to examine the clinical impact of decisions based on PSA velocity".
The conclusion of the study is that PSA velocity adds very little predictive value for determining the outcome of a first prostate biopsy in men with elevated PSA. These findings are very similar to those of earlier studies. "Accordingly, we see little justification for formal calculation of PSA velocity and subsequent incorporation into a statistical model, and no justification for velocity cut points, in determining indication for biopsy. This suggests that current guidelines on the use of PSAV to guide biopsy should be revised. However, we encourage use of clinical judgment in decisions about biopsy: A sudden rise in PSA might suggest prostatitis, triggering further evaluation of symptoms, laboratory tests, or empirical antibiotic therapy. If evidence of prostatitis is absent, a biopsy might well be advisable. This type of sophisticated, sequential, clinical decision making cannot easily be evaluated in analyses of population-based screening studies", says Professor Vickers.
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