Grade Groups Provide Improved Predictions of Pathological and Early Oncologic Outcomes Compared with Gleason Score...

Area of Science:

• Urologic Oncology
• Cancer Prognostics
• Pathology Reporting

Background:

• The Gleason score (GS) has historically been used to risk-stratify prostate cancer.
• Emerging evidence suggests the Grade Group (GG) system may offer improved risk stratification.
• The Michigan Urological Surgery Improvement Collaborative (MUSIC) database provides a robust dataset for comparative analysis.

Purpose of the Study:

• To compare the predictive performance of the Grade Group (GG) system versus the Gleason score (GS) system.
• To evaluate the ability of both systems to predict pathological outcomes and cancer recurrence after treatment.
• To assess the utility of GG and GS in risk-grouping prostate cancer patients.

Main Methods:

• Retrospective analysis of 8,052 patients who underwent biopsy and radical prostatectomy within the MUSIC database (March 2012 - June 2017).
• Patients were classified using both GG and GS systems.
• Logistic and Cox regression models were employed to compare outcomes, including extraprostatic extension, seminal vesicle invasion, lymph node positivity, positive surgical margins, and time to biochemical recurrence.

Main Results:

• The GG system demonstrated superior predictive power compared to the GS system for key pathological outcomes and recurrence.
• Higher GG scores (e.g., GG 3 vs. 2, GG 5 vs. 4) were significantly associated with increased risks of extraprostatic extension, seminal vesicle invasion, and positive lymph nodes.
• Patients with higher biopsy and radical prostatectomy GG scores showed a significantly shorter time to biochemical recurrence.

Conclusions:

• The Grade Group system provides better discrimination of recurrence-free survival between individual prostate cancer risk groups compared to Gleason score risk groups.
• Both biopsy and post-radical prostatectomy GG classifications incrementally associate with increased risk, highlighting its utility across different disease assessments.
• The GG system is a more effective tool for predicting pathological outcomes and cancer recurrence in prostate cancer patients.