The impact of PSA screening on prostate cancer mortality and overdiagnosis of prostate cancer in the United States.

BACKGROUND The study assessed the impact of prostate-specific antigen (PSA) testing in the United States by comparing the rates of PSA testing in U.S. counties to the rates of prostate biopsies and newly treated prostate cancer and to deaths from prostate cancer. METHODS We examined the association between the percentage of men aged 66-74 from a nationally representative 5% Medicare sample who received PSA testing in each U.S. county in 1997 and the percent of men who received prostate biopsies or treatment for newly diagnosed prostate cancer in 1997 as well as mortality from prostate cancer and from all other causes from 1998 to 2007. RESULTS Analyses of 1,067 U.S. counties showed a significant relationship between the rate of PSA testing and both the rate of men undergoing treatment for prostate cancer and prostate cancer mortality (both p < .001) but no relationship with mortality from other causes. For every 100,000 men receiving a PSA test in 1997, an additional 4,894 men underwent prostate biopsy and 1,597 additional men underwent prostate cancer treatment in 1997, and 61 fewer men died from prostate cancer during 1998-2006. Analyses stratified by age and race produced similar results. CONCLUSIONS PSA testing was associated with modest reductions in prostate cancer mortality and large increases in the number of men overdiagnosed with and overtreated for prostate cancer. The results are similar to those obtained by the large European randomized prospective trial of PSA testing.