Journal of the National Cancer Institute
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J. Natl. Cancer Inst. · Mar 2009
Comparative StudyLead time and overdiagnosis in prostate-specific antigen screening: importance of methods and context.
The time by which prostate-specific antigen (PSA) screening advances prostate cancer diagnosis, called the lead time, has been reported by several studies, but results have varied widely, with mean lead times ranging from 3 to 12 years. A quantity that is closely linked with the lead time is the overdiagnosis frequency, which is the fraction of screen-detected cancers that would not have been diagnosed in the absence of screening. Reported overdiagnosis estimates have also been variable, ranging from 25% to greater than 80% of screen-detected cancers. ⋯ The precise definition and the population used to estimate lead time and overdiagnosis can be important drivers of study results and should be clearly specified.
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J. Natl. Cancer Inst. · Feb 2009
Randomized Controlled Trial Multicenter StudyPotential surrogate endpoints for prostate cancer survival: analysis of a phase III randomized trial.
The identification of surrogate endpoints for prostate cancer-specific survival may shorten the length of clinical trials for prostate cancer. We evaluated distant metastasis and general clinical treatment failure as potential surrogates for prostate cancer-specific survival by use of data from the Radiation Therapy and Oncology Group 92-02 randomized trial. ⋯ Distant metastasis and general clinical treatment failure at 3 years may be candidate surrogate endpoints for prostate cancer-specific survival at 10 years. These endpoints, however, must be validated in other datasets.