Many urologists disagree with the recently published report of the US Preventive Services Task Force that questions the efficacy of PSA testing for prostate cancer . They are convinced that PSA testing is beneficial because it finds men with early prostate cancers that can be cured by surgery or radiation. While PSA testing can certainly do this, these same urologists rarely stop to consider the price paid to accomplish this goal. The present article by Boniol et al., researchers trained in the field of epidemiology, explores some of the consequences of PSA testing and identifies important issues that have an impact on the screening debate. First, they highlight the fact that the prevalence of clinically significant prostate cancer is considerably higher in Sweden when compared with the other ERSPC sites. This concept is critical to understanding how PSA performs as a screening test and why a lower prevalence of disease leads to more false-positive screening tests. Second, this problem is magnified when PSA testing is applied more frequently.
The practical implication is that annual PSA testing, as practised in many countries, leads to significant numbers of men with PSA elevations who subsequently undergo prostate biopsies. Many of the men biopsied will not have clinically significant disease. Most urologists treat this as a non-issue since they rarely encounter a problem. Unfortunately, health statistics suggest that two men in every 1000 die from complications associated with prostate biopsy . As Boniol et al. demonstrate, these numbers add up and rival the number of lives saved by PSA testing. In fact, a sensitivity analysis of their model suggests that the mortality rate from prostate biopsy is a significant public health concern that should receive greater attention. Urologists who are strong supporters of PSA testing may want to think critically about this alternative perspective.