Active surveillance is the standard of care for men with low-risk and selected men with favourable intermediate risk prostate cancer. The aim is to reduce the morbidity and mortality of overtreatment of non-clinically significant prostate cancer. A significant proportion progress to definitive treatment; it is therefore important to identify predictors of those that will progress, and to define the oncological outcomes of deferred treatment in these men. The published dataset is derived from a multi-institutional cohort of 7279 men managed with active surveillance. This study was undertaken through the Prostate Specialized Program of Research Excellence (SPORE) and aimed to examine parameters associated with time to definitive treatment in men initially managed by active surveillance. A third progressed to treatment after a median of 6.7 years (33.4%, 2260 men). Expected factors that led to giving up surveillance included higher grade, high stage, higher prostate specific antigen (PSA) values, and increased number of positive biopsy cores. Two important new observations have come out of this: a) Higher volume grade group I cancers progressed sooner than men with low volume disease, and b) there was no identifiable difference in the conversion rate based on race. Family history did not seem to influence time to conversion. Key limitations of this study are the lack of PSA-density and MRI data as these parameters were not utilised at the start of the study, and there is little / no information on comorbidities, interval PSA values and confirmatory and surveillance biopsies. Despite these drawbacks this is important data which will stimulate debate and further publications.