Association of absolute amount of pattern 4 disease on prostate biopsy with oncologic outcomes in intermediate-risk prostate cancer: A systematic review.

Introduction: Managing intermediate-risk prostate cancer (IRPC) is challenging due to the heterogeneity in patient outcomes within this risk category. Evaluating the absolute amount of Gleason pattern 4 disease (GP4) at biopsy using the total linear length of pattern 4 (GP4-TL) or absolute percentage of pattern 4 (APP4) may enhance risk stratification. This review aimed to determine if these absolute measures predict oncologic outcomes in IRPC and to identify optimal prognostic thresholds.

Methods: A systematic review was conducted following PRISMA guidelines. Studies included were those reporting the absolute amount of GP4 on biopsy and related outcomes in IRPC patients undergoing surgery or radiotherapy. Outcomes included biochemical recurrence, androgen deprivation therapy (ADT)-free survival, distant metastasis, prostate cancer-specific mortality, all-cause mortality, and adverse pathology.

Results: Seven studies with a total of 2523 patients were included. Analysis revealed that APP4 thresholds were highly predictive of biochemical recurrence, ADT-free survival, and distant metastasis. Both APP4 and GP4-TL were superior to relative %GP4 and Gleason grading (4+3 vs. 3+4) in predicting disease progression and mortality.

Conclusions: The absolute amount of GP4 shows consistent associations with important clinical outcomes and offers an accessible and established method to enhance risk stratification. Further research is needed to define optimal thresholds to guide treatment decisions.