Design-corrected variation by centre in mortality reduction in the ERSPC randomised prostate cancer screening trial.

To calculate design-corrected estimates of the effect of screening on prostate cancer mortality by centre in the European Randomised Study of Screening for Prostate Cancer (ERSPC).

The ERSPC has shown a 21% reduction in prostate cancer mortality in men invited to screening with follow-up truncated at 13 years. Centres either used pre-consent randomisation (effectiveness design) or post-consent randomisation (efficacy design).

In six centres (three effectiveness design, three efficacy design) with follow-up until the end of 2010, or maximum 13 years, the effect of screening was estimated as both effectiveness (mortality reduction in the target population) and efficacy (reduction in those actually screened).

The overall crude prostate cancer mortality risk ratio in the intervention arm vs control arm for the six centres was 0.79 ranging from a 14% increase to a 38% reduction. The risk ratio was 0.85 in centres with effectiveness design and 0.73 in those with efficacy design. After correcting for design, overall efficacy was 27%, 24% in pre-consent and 29% in post-consent centres, ranging between a 12% increase and a 52% reduction.

The estimated overall effect of screening in attenders (efficacy) was a 27% reduction in prostate cancer mortality at 13 years' follow-up. The variation in efficacy between centres was greater than the range in risk ratio without correction for design. The centre-specific variation in the mortality reduction could not be accounted for by the randomisation method.

Journal of medical screening. 2016 Aug 09 [Epub ahead of print]

Matti Hakama, Sue M Moss, Ulf-Hakan Stenman, Monique J Roobol, Marco Zappa, Sigrid Carlsson, Marco Randazzo, Vera Nelen, Jonas Hugosson

Finnish Cancer Registry, Helsinki, Finland., Centre for Cancer Prevention, Queen Mary University of London, London, UK ., Department of Clinical Chemistry, Helsinki University and HUSLAB, Helsinki, Finland., Department of Urology Erasmus University Medical Center, Rotterdam, The Netherlands., Unit of Clinical and Descriptive Epidemiology, ISPO, Florence, Italy., Department of Urology, Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden Department of Surgery (Urology), Memorial Sloan-Kettering Cancer Center, New York, NY, USA., Department of Urology, Cantonal Hospital Aarau, Aarau, Switzerland Department of Urology, University Hospital Zürich and University of Zürich, Switzerland., Provincial Instituut voor Hygiene, Antwerp, Belgium., Department of Urology, Sahlgrenska Academy at Gothenburg University, Gothenburg, Sweden.