A Randomized Trial of Early Detection of Clinically Significant Prostate Cancer (ProScreen)

A population-based randomised trial of prostate cancer screening will be carried out. A total of approximately 117,200 men aged 50-63 in Helsinki and Tampere are randomised to intervention (screening) or control arm. A reduction in harms of screening in the form of overdiagnosis is sought, while retaining as much as possible of the mortality benefit (reduction in prostate cancer mortality). Novel methods that have been shown to increase specificity for clinically relevant prostate cancer but never tested in a randomised setting will be employed in screening and diagnostics. The main end-point is prostate cancer mortality at 10 and 15 years of follow-up.

Frequent adverse effects have so far tipped the balance of benefits and harms against prostate cancer screening, and therefore the investigators will focus on employing the best possible means for reducing them. The project introduces a novel concept for PC screening that minimises overdiagnosis and overtreatment, while retaining the mortality benefit to shift the balance of screening benefits and harms to a favourable net effect. The strategy for implementation as a randomised screening trial utilises three levels of risk assessment (PSA, kallikrein panel and MRI) before the diagnostic procedure (prostate biopsy), each aimed at eliminating detection of indolent disease. The study hypothesis is that by virtue of the novel three-tiered screening algorithm, the beneficial screening effect (prostate cancer mortality reduction) can be retained, while the overdiagnosis can be largely eliminated. The impact of an integrative approach has never been evaluated - each of the methods has only been assessed in isolation. The breakthrough potential of the proposal lies in combining the three novel approaches and taking them to the forefront of applied research through a randomised trial. The key impact of the study is in defining whether the overall balance of benefits and harms of prostate cancer screening can be reversed by applying the best possible methods to detect only clinically important disease. If the study hypothesis is affirmed, it opens the way to introduction of prostate cancer screening. If the balance of harms and benefits is still unfavourable, the problem of overdiagnosis in prostate cancer may be intractable.