They used the Preventive Project (MPP) in Malmö, Sweden; a cardiovascular study enrolling a representative cohort (74% participation) of men aged 33 - 50 between 1974-1986. The retrieval and analysis of archived blood plasma from MPP was previously used to demonstrate a strong association between PSA levels measured at age 44-50 and risk of advanced prostate cancer diagnosis up to 30 years subsequently. This study sought to determine the degree of “risk concentration”, meaning the proportion of cases found in men with the highest PSA levels. The death from CaP was determined by case note review or from death certificate data. A nested case-control design was used, with three controls matched to each death. Lorenz curve methodology was used to determine risk concentration.
The median follow up was 27 years and a total of 141 men died from prostate cancer. A single PSA at age 44-50 was strongly predictive of subsequent CaP death at a median follow-up of 27 years (AUC: 0.72). The Lorenz curve for risk concentration demonstrated 44% of deaths occurred in men with the top 10% of PSA. They also studied the top quartile of men, measured free PSA and hK2, and took those at highest risk on the basis of a combined model of all markers. This resulted in the identification of an additional 2.4% of deaths in the top 10% of risk. Using 215 metastasis events as the endpoint, the results were similar with 42% of metastases occurring in top 10% of PSA levels with an additional 2.5% metastases identified by free PSA and hK2. He concluded that targeting the 10% of men identified at highest risk in an early intervention strategy could prevent almost half of all prostate cancer deaths.
Presented by Andrew Vickers, et al. at the American Urological Association (AUA) Annual Meeting - May 14 - 19, 2011 - Walter E. Washington Convention Center, Washington, DC USA
Reported for UroToday by Christopher P. Evans, MD, FACS, Professor and Chairman, Department of Urology, University of California, Davis, School of Medicine.