Will the modification of the Gleason grading system affect the urology practice?

Area of Science:

• Urology
• Pathology
• Oncology

Background:

• Accurate prostate cancer grading is crucial for treatment decisions.
• The conventional Gleason grading system has limitations in differentiating tumor aggressiveness.
• The modified Gleason grading system aims to improve grading accuracy.

Purpose of the Study:

• To evaluate the impact of the modified Gleason grading (mGG) system on score discrepancies between needle biopsy (NB) and radical prostatectomy (RP).
• To assess how modified Gleason scores influence nomogram predictions for prostate cancer.
• To compare the diagnostic agreement between NB and RP using conventional Gleason grading (cGG) versus mGG.

Main Methods:

• Retrospective analysis of 97 patients undergoing NB and RP.
• Comparison of Gleason scores assigned by cGG and mGG systems.
• Evaluation of agreement rates between NB and RP specimens for both grading systems.
• Analysis of nomogram predictions using cGG versus mGG scores.

Main Results:

• A new Gleason score was assigned in 41.2% of NB and 15.5% of RP specimens with mGG.
• Agreement between NB and RP improved from 31.9% to 44.3% with mGG.
• mGG led to higher predicted pathological stages and lower life expectancy predictions in nomograms.
• Significant differences were observed for both NB and RP specimen re-grading (P < .001 and P = .005, respectively).

Conclusions:

• The modified Gleason grading system significantly alters prostate cancer grading compared to the conventional system.
• While mGG improves concordance between needle biopsy and radical prostatectomy findings, it affects nomogram-based predictions.
• Clinicians must consider these changes when interpreting nomogram results and making therapeutic decisions.