The balance of benefits and harms in prostate cancer screening has not been sufficiently characterized. We related indicators of mortality reduction and overdetection by center within the European Randomized Study of Prostate Cancer Screening.
We analyzed the absolute mortality reduction expressed as number needed to invite (NNI=1/absolute risk reduction; indicating how many men had to be randomized to screening arm to avert a prostate cancer death) for screening and the absolute excess of prostate cancer detection as number needed for overdetection (NNO=1/absolute excess incidence; indicating the number of men invited per additional prostate cancer case), and compared their relationship across the seven ERSPC centers.
Both absolute mortality reduction (NNI) and absolute overdetection (NNO) varied widely between the centers: NNI 200-7000 and NNO 16-69. Extent of overdiagnosis and mortality reduction were closely associated (correlation coefficient r=0.76, weighted linear regression coefficient β=33, 95% 5-62, R2=0.72). For an averted prostate cancer death at 13 years of follow-up, 12-36 excess cases had to be detected in various centers.
The differences between the ERSPC centers likely reflect variations in prostate cancer incidence and mortality, as well as in screening protocol and performance. The strong interrelation between the benefits and harms suggests that efforts to maximize the mortality effect are bound to increase overdiagnosis, and might be improved by focusing on high-risk populations. The optimal balance between screening intensity and risk of overdiagnosis remains unclear.
Clinical cancer research : an official journal of the American Association for Cancer Research 2015 Aug 19 [Epub ahead of print]
Anssi Auvinen, Sue Moss, Teuvo L J Tammela, Kimmo Taari, Monique Roobol, Fritz H Schröder, Chris H Bangma, Sigrid Carlsson, Gunnar Aus, Marco Zappa, Donella Puliti, Louis J Denis, Vera Nelen, Maciej Kwiatkowski, Marco Randazzo, Alvaro Paez, Marcos Lujan, Jonas Hugosson
School of Health Sciences, University of Tampere anssi auvinen@uta fi , Centre for Cancer Prevention, Queen Mary University of London, Wolfson Institute of Preventive Medicine , University of Tampere, University of Tampere , Department of Urology, Helsinki University Central Hospital , Department of Urology, Erasmus University , Department of Urology, Erasmus Medical School , Urology, Chairman of the Erasmus MC Department of Urology - Erasmus MC - Rotterdam , Memorial Sloan Kettering Cancer Center , Department of Urology, Sahlgrenska Academy at University of Gothenburg , Clinical and Descriptive Epidemiology Unit, ISPO Cancer Prevention and Research Insitute , ISPO Cancer Prevention and Research Institute , Provincie Antwerpen, Provinciaal Instituut voor Hygiene , Provincie Antwerpen, Provinciaal Instituut voor Hygiene , Department of Urology, Cantonal Hospital Aarau , Department of Urology, Universiity Hospital Zurich , Department of Urology, Hospital Universarsitario de Fuenlabrada , Department of Urology, Hospital Universitaria Infanta Cristina , Department of Urology, Sahlgrenska Academy at University of Gothenburg