Urine markers as possible tools for prostate cancer screening: review of performance characteristics and practicality

BACKGROUND: In recent years, an increasing number of urine-based tests have been proposed as potential screening tests for prostate cancer. The goal of this review was to summarize the current status of evidence regarding performance characteristics of the proposed tests and their practicality under screening conditions. METHOD: Relevant articles published up to and including May 2005 were identified in the PubMed database. At least 10 cases and 10 controls had to be analyzed for a study to be included in the review. Data concerning the study population, performance characteristics, and the collection and processing of urine samples were extracted from the reviewed articles. RESULTS: In all, 34 retrospective studies evaluating 21 different markers complied with the inclusion criteria. Most of the studies were rather small and included heterogeneous clinical study populations. Promising results were reported for a few markers in single studies, but they have often not been replicated in subsequent larger studies. Some of the more promising results were obtained with 24-h urines or with specimen-handling procedures that might be difficult to perform under screening conditions. CONCLUSIONS: Larger studies with a prospective design are required to confirm promising findings regarding performance characteristics of some novel markers recently reported in mostly small studies. Future studies should also pay particular attention to the practicality of the markers under screening conditions.