In 1999, the TAPG group initiated the "Prognostic Factors in Prostate Cancer for Patients Treated by Watchful Waiting" study, referred to as the TAPG study. It is a retrospective population-based tissue sample study in men diagnosed with localised prostate cancer 1990-2006, inclusively. Initially the cohort comprised men diagnosed with prostate cancer with transurethral resection of the prostate (TURP) and needle biopsies 1990-1996, but was expanded from 2005 to include men diagnosed with prostate cancer 1990 - 2006. Data was collected from six regional cancer registries and eligibility was confirmed via hospital sites, which sent the relevant tissue samples to the TAPG Central Coordinating Office (CCO). Selection of eligible patients for the study completed in 2010. Since this year the TAPG CCO has been collecting cancer registration and mortality updates on the cohort members from regional cancer registries.