Should we abstain from Gleason score 2–4 in the diagnosis of prostate cancer? Results of a German multicentre study

The new ISUP 2014/WHO 2016 prostate cancer grade group system: first résumé 5 years after introduction and systemic review of the literature

PURPOSE

To systematically and comprehensively review and summarize the most recent literature assessing the value of the new grading system introduced by the International Society of Urological Pathology (ISUP) in 2014 and accepted by the World Health Organization (WHO) in 2016.

METHODS

A systematic literature search in the PubMed database was performed up to November 2018. Overall, 15 studies in the period from 2016 to 2018 evaluating the new grading system have been selected for evidence synthesis.

RESULTS

The main goals of the new ISUP 2014/WHO 2016 grading system were to establish (I) a more accurate and simplified grade stratification, (II) less overtreatment of indolent prostate cancer as well as (III) an improved patient communication. The majority of the studies chose biochemical recurrence as an endpoint for evaluation and statistically assigns the new ISUP 2014/WHO 2016 grading system a higher prognostic accuracy than the former Gleason grading. However, in only a subset of studies it was clearly evident that the historical samples were not only re-grouped according to the new grade groups but also re-graded according to the new histomorphological 2014 ISUP criteria.

CONCLUSIONS

The vast majority of the studies support an improved prognostic accuracy of the ISUP 2014/WHO 2016 grade groups and endorse its worldwide application.

Temporal changes in the pathologic assessment of prostate cancer

Thirty years have witnessed dramatic changes in the manner in which we diagnose and manage prostate cancer. With prostate-specific antigen screening, there was a shift towards smaller, clinically localized tumors. Tumors are often multifocal and display phenotypic and molecular heterogeneity. Pathologic evaluation of tissue obtained by needle biopsy remains the gold standard for the diagnosis and risk assessment of prostate cancer. Years of experience with grading, along with changes in the amount of biopsy tissue obtained and diagnostic tools available, have produced shifts in grading practices among genitourinary pathologists. Trends in Gleason grading and advances in pathological risk assessment are reviewed with particular emphasis on recent Gleason grading modifications of the International Society of Urologic Pathology. Efforts to maximize the amount of information from pathological specimens, whether it be morphometric, histochemical, or molecular, may improve predictive accuracy of prostate biopsies. New diagnostic techniques are needed to optimize management decisions.