This study aimed to determine the association between the length of Gleason pattern (GP) 4 in prostate biopsies and post-prostatectomy oncologic outcomes in patients with Gleason Score 7 prostate cancer.
The researchers compared four methods of quantifying GP4: maximum %GP4 in any single core, overall %GP4, total length of GP4 (mm) across all cores, and length of GP4 (mm) in the highest volume core. They assessed these methods’ ability to predict biochemical recurrence-free survival after radical prostatectomy using multivariable Cox proportional hazards regression.
A total of 457 men with grade group 2 prostate cancer on biopsy underwent radical prostatectomy. The 3-year biochemical recurrence-free survival probability was 85%. On multivariable analysis, all four GP4 quantification methods were associated with biochemical recurrence: maximum %GP4 (HR=1.30), overall %GP4 (HR=1.61), total length GP4 (HR=2.48), and length GP4 in the highest core (HR=1.32). However, no significant differences were found between the methods due to a relatively low event rate.
The study concludes that further research on GP4 quantification, along with the ratio of GP3 to GP4, is needed to classify prostate cancer risk. Additionally, studies should explore whether GP4 quantification can serve as a surrogate endpoint for disease progression in active surveillance trials.
