Gleason Score 6 - Prostate Cancer or Benign Variant?

The leading motivation behind wanting to call a 'malignant' prostate lesion 'benign' is the evidence of indolent prostate cancer that is not associated with a fatal outcome and in part makes therapeutic measures such as surgery and radiotherapy appear like overtreatment for some or possibly the majority of such patients. The present article reviews the definitions of 'precancerous lesion' and 'cancer' from a histopathologic point of view as the basis and gold standard for diagnosis. It is clear that with the 2 modifications implemented since its first publication, the Gleason score as the grading system for prostate cancer has shifted towards a low malignant subgroup diagnosed as Gleason 6. The recommendation of the International Society of Urological Pathology to change the Gleason score to a 5-tiered system, starting with grade group 1, is presented here, and may help doctor-patient communication especially in the active surveillance setting.