A systematic review of the diagnostic accuracy of prostate specific antigen

BACKGROUND Prostate cancer is the fourth commonest cancer in the UK, and the incidence is rising. The reference standard for diagnosing this condition is prostate biopsy, an invasive procedure. This study systematically reviews recent literature on tPSA accuracy. The time period was restricted to ensure that the estimates referred to contemporary tPSA tests and prostate cancer reference standards. The focus of this review was restricted to European populations as tPSA levels are known to vary by population group. METHODS Medline was searched (from 01/1998 to 01/2008) and Embase (from 01/1998 to 01/2008), which returned 3087 citations. These were assessed by 6 reviewers, who shortlisted 54 of possible relevance. 2 reviewers assessed each using the following inclusion criteria: data collection between 1998-2008; tPSA measurements for all participants; histological confirmation of the diagnosis; samples from a European population and sufficient data to calculate 2 x 2 tables. The final set of 10 included studies represented 5373 participants. Quality of the included studies was assessed in duplicate using criteria suggested by the Cochrane Collaboration. Review Manager 5.0 software was used to analyse the data, including plotting a series of summary receiver operator curve spaces (SROC). RESULTS tPSA sensitivities ranged from 0.78 to 1.00 and specificities from 0.06 to 0.66. Positive likelihood ratios ranged from 0.83 to 2.90 and negative likelihood ratios ranged from 0.00 to 3.75 CONCLUSION tPSA has a role to play as one of several indicators for prostate biopsy along with abnormal digital rectal examination and urinary symptoms. However, tPSA test has a high false positive and significant false negative rate. It is important that clinicians understand these limitations.