Study population
The ICPCG study cohort has been described in detail previously (Schaid and Chang 2005; Xu et al. 2005). Fifteen groups participated in the present study, including those from Europe [Finland (Tampere University), Sweden (Karolinska Institute), UK (Institute of Cancer Research and Royal Marsden NHS Foundation Trust, University of Cambridge, ACTANE), Germany (University of Ulm), and France (CeRePP)], North America (Fred Hutchinson Cancer Research Center, Johns Hopkins Hospital, Louisiana State University, Mayo Clinic, McGill University, Northwestern University, Stanford University, University of Michigan, and University of Utah), and Australia (University of Melbourne) (Supplementary Table 1).
Each ICPCG group recruited its study population via different methods of pedigree ascertainment and utilized different methods to confirm prostate cancer diagnosis. In this study, men were considered “affected” if their prostate cancer diagnosis was confirmed by either medical records or death certificates. All other men were assigned as “unknown phenotype.” A total of 2,443 families were included in the study, including 6,422 affected men and 1,902 men without a prostate cancer diagnosis (unknown), and 1,803 women whose DNA samples were available (Supplementary Table 1). Research protocols and study documentation were approved by each group’s Institutional Review Board.