Prostatic Adenocarcinoma: A Grading from Gleason to the New Grade-Group System: A Historical and Critical Review

Abstract

The introduction of the Gleason grading system revolutionised prognostic parameters and determination of<br />patient treatment regiments for prostatic adenocarcinomas, and has become synonymous with prostate cancer, almost<br />universally applied in clinical settings to predict radical prostatectomy specimen findings, potential biochemical failure,<br />local recurrences, lymph nodes or distant metastases in patients not receiving any treatment as well as those receiving<br />treatment including radiation therapy, surgical treatment such as radical prostatectomy and other therapies etc,. However,<br />characterisation and classification of prostate cancer is very different compared to 40-50 years ago when Gleason scores<br />were first introduced. Despite this radical shift in classification, the Gleason system has remained one of the most<br />important prognostic factors in prostate cancer, only possible as a result of timely and appropriate modifications to<br />this characterisation system made in 2005 and 2014. However, even after these modifications, certain limitations of<br />the Gleason system remain, due to which a new prostate cancer prognostic grade group system was introduced in 2014,<br />which was widely accepted in the 2014 ISUP consensus conference, and incorporated into the WHO classification of<br />thetumor of the Urinary System and Male Genital Tract in 2016. Herein, this article will discuss how this new prognostic<br />grade group system, which is regarded as simpler and more accurate than the Gleason system risk stratification groups,<br />will be used in conjunction with the Gleason system to improve patient prognosis and treatment.