Effects of Screening on Radical Prostatectomy Efficacy: The Prostate Cancer Intervention Versus Observation Trial

Abstract

If RP efficacy and prostate cancer survival in the absence of screening are similar to that in the SPCG-4 trial, then overdiagnosis and lead time largely explain the lower AMD in PIVOT. If these artifacts of screening are the correct explanation, then there is a subset of case subjects that should not be treated with RP, and identifying this subset should lead to a clearer understanding of the benefit of RP in the remaining cases.

Measures of survival benefit in cancer drug development and their limitations

“…Thus, even though the two trials produced similar results in terms of relative hazards, the NNT for the PIVOT trial was considerably higher; the lower baseline risk of death in that trial meant that there were fewer lives to save even under a hazard ratio that was almost the same as in the SPCG-4 trial. A recent study that examined these results and attempted to reconcile them 4 concluded that differences in the prevalence of PSA screening in the two case populations largely explained the discrepancies between the trials in the observed frequency of prostate cancer deaths and survival.…”

The Risks and Benefits of Current Treatment Options for Prostate Cancer and Future Possibilities in Advanced Imaging and Targeted Therapy: A Review

“…The insignificance of mortality reductions by radical intervention observed in the Prostate Cancer Intervention versus Observation Trial (PIVOT) study reflect in part the more favorable prognosis of patients with tumors detected by PSA screening. The resulting lead time and increased rates of overdiagnosis have led to a greater number of low risk, clinically insignificant tumors that naturally yield better outcomes [16,30].…”

Implementation of PSA-based active surveillance in prostate cancer

“…In fact, many CaPs would never have become clinically significant or caused any impairment to the quality or quantity of life if they remained undetected, and are thus said to be overdiagnosed [19,20]. It is estimated that 32% of screen-detected cancers were overdiagnosed and that the mean lead time defined as the time between the screening and subsequent diagnosis and the time the disease would have been diagnosed without screening was 7.7 years among nonoverdiagnosed men [21]. A multiplicity of CaP risk assessment instruments have been designed to classify the patients and predict disease outcomes, all of which include PSA level [22][23][24][25][26][27][28].…”