The percentage of high‐grade prostatic adenocarcinoma in prostate biopsies significantly improves on Grade Groups in the prediction of prostate cancer death

Abstract

Aims It has been recommended that the percentage of high‐grade (HG) Gleason patterns 4 and 5 should be quantified in prostate cancer. However, this has not been assessed in a cohort using prostate cancer death as an outcome, and there is debate as to whether the biopsy with the ‘worst’ percentage of HG disease or an ‘overall’ percentage of HG disease should be reported. Such data may assist in active surveillance decisions. Methods and results Men with clinically localised prostate cancer diagnosed by needle biopsy from 1990 to 2003 were included. The endpoint was prostate cancer death. Clinical variables included Gleason score (GS), prostate‐specific antigen level, age, clinical stage, and disease extent. Deaths were divided into those from prostate cancer and those from other causes, according to World Health Organization criteria. Nine hundred and eighty‐eight biopsy cases were centrally reviewed according to criteria agreed at the Chicago International Society of Urological Pathology conference in 2014. Cores were given individual GSs and Grade Groups (GGs), and a percentage of each grade was given for each core. Both the worst percentage of HG disease seen in a biopsy series and overall percentage of HG disease were calculated. The overall percentage of HG disease was highly significant, with a hazard ratio of 4.45 for the interquartile range (95% confidence interval 3.30–6.01, P < 2.2 × 10−16), and was similar to the percentage of HG disease seen in the worst core. In multivariate analysis, both were highly significant. GG2 cases with ≤5% Gleason pattern 4 showed similar survival to GG1 cases. Conclusions These data validate the use of percentage of HG disease to predict prostate cancer death. As both worst and overall percentage of HG disease are powerful predictors of outcome, either could be chosen to provide prognostic information.

Predicting Prostate Cancer Death with Different Pretreatment Risk Stratification Tools: A Head-to-head Comparison in a Nationwide Cohort Study

“…The overall percentage of Gleason grade 4 on both radical prostatectomy and biopsy samples has been shown to be an independent predictor of adverse pathology at RP (174)(175)(176)(177), BCR (166,174,(176)(177)(178) and prostate cancer death among men with GG2 and/or GG3 (179). The overall percentage of Gleason grade 4 has been shown to outperform the maximum percentage of Gleason pattern 4 (174,180).…”

The 2019 Genitourinary Pathology Society (GUPS) White Paper on Contemporary Grading of Prostate Cancer

“…37 Studies demonstrating essentially no difference in adverse pathology at radical prostatectomy between needle biopsy Grade Group 2 with small percent Gleason pattern 4 and contemporaneous Grade Group 1 patients may bolster this approach. 20,[22][23][24]38,39 In cases with truly minimal quantities of Gleason pattern 4, having to assign a small increment (eg, ,5%) should prompt the pathologist to verify the presence of Gleason pattern 4 by examining multiple tissue levels and to exclude tangential sectioning. 26 Using smaller increments also allows for calculation of overall percent and total millimeters of Gleason pattern 4 for the whole biopsy, which have been shown in some of the largest studies to correlate with adverse pathology at radical prostatectomy.…”

Prostate cancer grading, time to go back to the future

“…Gleason pattern. The issue has been compounded by the plethora of terms and abbreviations that have flooded the literature, with the grading system being referred to as: GG (grade group) [3]; GrG (grade group) [4]; PGG (prognostic grade group [5]; prostate cancer grade group [6]); GGG (Gleason grade group) [7]; ISUP grade [8]; WHO grade group [9]; ISUP grade group [10]; ISUP score [11]; and others. The problems resulting from the use of 'GG' as an acronym are not confined to the confusion as to whether it refers to ‘grade group’ or Gleason grade (i.e.…”