ARTICLES Overdiagnosis Due to Prostate-Specific Antigen Screening: Lessons From U.S. Prostate Cancer Incidence Trends

tate cancer is considered a major potential drawback of prostate-specific antigen (PSA) screening. Quantitative esti-mates of the magnitude of this problem are, however, lack-ing. We estimated rates of prostate cancer overdiagnosis due to PSA testing that are consistent with the observed inci-dence of prostate cancer in the United States from 1988 through 1998. Overdiagnosis was defined as the detection of prostate cancer through PSA testing that otherwise would not have been diagnosed within the patient’s lifetime. Meth-ods: We developed a computer simulation model of PSA testing and subsequent prostate cancer diagnosis and death from prostate cancer among a hypothetical cohort of two million men who were 60–84 years old in 1988. Given values for the expected lead time—that is, the time by which the test advanced diagnosis—and the expected incidence of prostat