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Abstract:
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The efficacy of prostate-specific antigen (PSA) screening for prostate cancer has been uncertain since it first entered clinical practice. The European Randomized Study of Screening for Prostate Cancer (ERSPC) and the Prostate, Lung, Colorectal, and Ovarian cancer screening trial (PLCO) were conducted to provide definitive answers about screening efficacy. Rather than resolving questions, the trials have exacerbated long-standing uncertainty about whether screening benefits cancer survival with apparently conflicting results. Pervious study did not take into account of implementation details such as screening patterns. We use a two-step approach to formally test whether screening efficacy differs between the ERSPC and PLCO using mean lead time as a surrogate of screening intensity. The mean lead time is the mean time to diagnosis without screening minus the mean time to diagnosis with screening. The model jointly estimates screening effect on cancer survival and mortality for different screening trials while accounting for differences in screening and diagnosis between trial arms. Application using data from two screening trials and SEER are presented.
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