In an article by Sieler et al published in BJUI (2012), histology from patients treated for prostate cancer with active surveilance (AS) were studied. AS was offered to patients with an estimated life expectancy of more than 10 years who fulfilled the following criteria, as described by Epstein et al : no Gleason pattern 4 or 5 at prostate biopsy, ≤2 positive biopsy cores, <50% tumour involvement of the biopsy cores and a PSA density <0.15 ng/mL/ccm. Patients were followed every 6 months with an annual rebiopsy until the age of 76. Disease reclassification to a higher risk was defined as either PSA progression (PSA doubling time ≤3 years) or biopsy progression (≥50% core involvement and/or ≥3 positive biopsy cores and/or Gleason pattern 4 or 5). Those patients fulfilling the initial criterion had a higher proportion of organ-confined cancers (89.7% vs 59.1%, P = 0.02) and fewer positive surgical margins (25.6% vs 40.9%) than others. The authors concluded that AS is safe, but encourage strict adherence to the Epstein criterion.