Gleason pattern 4 length and active surveillance eligibility in Grade Group 2-4 prostate cancer

To evaluate whether total Gleason pattern 4 (GP4) length provides better risk stratification than current risk group criteria for determining potential active surveillance (AS) eligibility, using oncological outcomes after radical prostatectomy (RP).

We identified patients with Grade Group (GG) 2-4 disease on magnetic resonance imaging (MRI)-targeted and systematic biopsy who underwent RP. We calculated total GP4 length as the summed millimetres of GP4 in systematic cores plus the average across MRI-targeted cores. Concordance analysis was used to evaluate how increasing GG corresponded to greater GP4 burden. We compared prediction of adverse pathology at RP and 5-year biochemical recurrence (BCR) between risk groups and total length of GP4.

Among 2499 patients, 1691, 694, and 114 had GG2, GG3, and GG4 disease, of whom 73%, 19%, and 15% had low amounts (<2 mm) of GP4. Patients with <2 mm of GP4, regardless of GG, had similar risks of adverse pathology (5.2% vs 5.0%) and 5-year BCR (20% vs 21%) as those with favourable intermediate-risk disease; if used as an AS threshold, <2 mm of GP4 would classify approximately twice as many patients as AS eligible, translating to ~50 000 men annually in the United States alone.

Total length of GP4 provides better risk stratification for AS eligibility than current favourable intermediate-risk group criteria. Further defining the optimal method for GP4 quantification and determining the appropriate cut-point is needed before clinical implementation.