Overdiagnosis in PSA Screening

If screening detects only those cancers destined to become clinically evident, the cumulative incidence of cancer in a screened population (sum of clinically detected plus screening-detected cases) would, over time, approximate the incidence without screening. But if screening detects cancers that otherwise would have remained clinically silent, the long-term cancer incidence in a screened population would rise because of overdetection of clinically unimportant cases.

To estimate overdetection of prostate cancer with prostate-specific antigen (PSA) screening, researchers used epidemiologic data from the National Cancer Institute to compare the incidence of prostate cancer during the PSA era (1987–2005) with the incidence in the baseline pre-…